Occupational Exposure to Tuberculosis

DEPARTMENT OF LABOR

Occupational Safety and Health Administration

29 CFR Part 1910

[Docket No. H-371]

RIN 1218-AB46

Occupational Exposure to Tuberculosis

AGENCY: Occupational Safety and Health Administration (OSHA), Labor

ACTION: Proposed rule and notice of public hearing.

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SUMMARY: The Occupational Safety and Health Administration is proposing

a health standard, to be promulgated under section 6(b) of the

Occupational Safety and Health Act of 1970, 29 U.S.C. 655, to control

occupational exposure to tuberculosis (TB). TB is a communicable,

potentially lethal disease that afflicts the most vulnerable members of

our society: the poor, the sick, the aged, and the homeless. As many as

13 million U.S. adults are presently believed to be infected with TB;

over time, more than 1 million of these individuals may develop active

TB disease and transmit the infection to others. TB remains a major

health problem with 22,813 active cases reported in the U.S. in 1995. A

number of outbreaks of this disease have occurred among workers in

health care settings, as well as other work settings, in recent years.

To add to the seriousness of the problem, some of these outbreaks have

involved the transmission of multidrug-resistant strains of

Mycobacterium tuberculosis, which are often fatal. Although it is the

responsibility of the U.S. Public Health Service to address the problem

of tuberculosis in the general U.S. population, OSHA is solely

responsible for protecting the health of workers exposed to TB as a

result of their job.

OSHA estimates that more than 5 million U.S. workers are exposed to

TB in the course of their work: in hospitals, homeless shelters,

nursing homes, and other work settings. Because active TB is endemic in

many U.S. populations, including groups in both urban and rural areas,

workers who come into contact with diseased individuals are at risk of

contracting the disease themselves. The risk confronting these workers

as a result of their contact with TB-infected individuals may be as

high as 10 times the risk to the general population. Although the

number of reported cases of active TB has slowly begun to decline after

a resurgence between 1985-1992, 16 states reported an increase in the

number of TB cases in 1995, compared with 1994. Based on a review of

the data, OSHA has preliminarily concluded that workers in hospitals,

nursing homes, hospices, correctional facilities, homeless shelters,

and certain other work settings are at significant risk of incurring TB

infection while caring for their patients and clients or performing

certain procedures. To reduce this occupational risk, OSHA is proposing

a standard that would require employers to protect TB-exposed employees

by means of infection prevention and control measures that have been

demonstrated to be highly effective in reducing or eliminating job-

related TB infections. These measures include the use of respirators

when performing certain high hazard procedures on infectious

individuals, procedures for the early identification and treatment of

TB infection, isolation of individuals with infectious TB in rooms

designed to protect those in the vicinity of the room from contact with

the microorganisms causing TB, and medical follow-up for occupationally

exposed workers who become infected. OSHA has preliminarily determined

that the engineering, work practice, and administrative controls,

respiratory protection, training, medical surveillance, and other

provisions of the proposed standard are technologically and

economically feasible for facilities in all affected industries.

DATES: Written comments on the proposed standard must be postmarked on

or before December 16, 1997 and notices of intention to appear at the

informal rulemaking hearings must be postmarked on or before December

16, 1997.

Parties requesting more than 10 minutes for their presentation at

the hearings and parties submitting documentary evidence at the hearing

must submit the full text of their testimony and all documentary

evidence no later than December 31, 1997.

The informal public hearings will begin at 10:00 a.m. on the first

day of hearing and at 9:00 a.m. on each succeeding day. The informal

public hearings will be held in Washington, D.C. and are scheduled to

begin on February 3, 1998.

ADDRESSES: Hearings will be held in the Auditorium of the U.S.

Department of Labor (Frances Perkins Building), 200 Constitution

Avenue, NW, Washington, D.C. Subsequent additional informal public

hearings will be held in other U.S. locations. A Federal Register

notice will be issued upon determination of the locations and dates of

these hearings.

Comments on the proposed standard, Notices of Intention to Appear

at the informal public hearings, testimony, and documentary evidence

are to be submitted in quadruplicate to the Docket Officer, Docket No.

H-371, Room N-2625, U.S. Department of Labor, 200 Constitution Ave.,

NW, Washington, DC 20210, telephone (202) 219-7894. Comments of 10

pages or fewer may be transmitted by fax to (202) 219-5046, provided

the original and three copies are sent to the Docket Officer

thereafter. The hours of operation of the Docket Office are 10:00 a.m.

until 4:00 p.m.

Written comments, Notices of Intention to Appear at the informal

rulemaking hearings, testimony, documentary evidence for the hearings,

and all other material related to the development of this proposed

standard will be available for inspection and copying in the Docket

Office, Room N-2625, at the above address.

FOR FURTHER INFORMATION CONTACT: Bonnie Friedman, Office of Information

and Consumer Affairs, Occupational Safety and Health Administration,

Room N-3647, U.S. Department of Labor, 200 Constitution Ave., NW,

Washington, DC 20210, Telephone (202) 219-8148, FAX (202) 219-5986.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction

II. Pertinent Legal Authority

III. Events Leading to the Proposed Standard

IV. Health Effects

V. Preliminary Risk Assessment

VI. Significance of Risk

VII. Preliminary Economic and Regulatory Flexibility Analysis

VIII. Unfunded Mandates

IX. Environmental Impact

X. Summary and Explanation of the Proposed Standard

XI. Public Participation--Notice of Hearing

XII. Authority and Signature

XIII. The Proposed Standard

References to the rulemaking record are in the text of the

preamble. References are given as ``Ex.'' followed by a number to

designate the reference in the docket. For example, ``Ex. 1'' means

exhibit 1 in the Docket H-371. This document is a copy of the petition

for a permanent standard filed by the Labor Coalition to Fight TB in

the Workplace on August 25, 1993. A list of the exhibits and copies of

the exhibits are available in the OSHA Docket Office.

[[Page 54161]]

I. Introduction

The preamble to the Proposed Standard for Occupational Exposure to

Tuberculosis discusses the events leading to the development of the

proposed standard, the health effects of exposure to tuberculosis, and

the degree and significance of the risk. An analysis of the

technological and economic feasibility of the proposal and an

explanation of the rationale supporting the specific provisions of the

proposed standard are also included.

Public comment on all matters discussed in this notice and all

other relevant issues is requested for the purpose of assisting OSHA in

the development of a new standard for occupational exposure to

tuberculosis.

A. Issues

OSHA requests comment on all relevant issues discussed in this

preamble, including the health effects, risk assessment, significance

of risk determination, technological and economic feasibility and

requirements that should be included in the final standard. OSHA is

especially interested in responses, supported by evidence and reasons,

to the following questions. This list is provided to assist persons in

formulating comments, but is not intended to be all inclusive or to

indicate that participants need to respond to all issues or follow this

format. Please give reasons for your answers and provide data when

available.

Specific issues of concern to OSHA are the following:

Health Effects

1. What, if any, additional studies or case reports on TB should be

included in the health effects analysis?

2. Is there information that will provide data for estimating the

rise in Multidrug-resistant TB (MDR-TB)? Is the rise in MDR-TB a

serious threat?

Risk Assessment

1. Are there alternative risk assessment methodologies available?

What are they? Are there other studies available that would be useful

for assessing risk?

2. Are there factors other than or in addition to the ones OSHA has

chosen that would be useful in estimating the background risk for TB?

Technological and Economic Feasibility

1. Are OSHA's estimates of the numbers and types of workers

currently exposed to M. tuberculosis reasonable? If not, please provide

estimates of the number of workers currently at risk and the percentage

of the total workforce these workers represent, by industry.

2. Are OSHA's estimates of controlled access rates (i.e., the

percentage of workers currently at risk who would remain at risk after

employers minimize the number of workers exposed to individuals with

suspected or confirmed infectious TB) reasonable? If the number of

workers exposed to individuals with suspected or confirmed infectious

TB is minimized, by what percentage could the number of workers at risk

be reduced in each affected industry? In each industry, what are the

job categories that would continue to be occupationally exposed?

3. Are OSHA's estimates of the numbers of affected establishments

reasonable? If not, please provide estimates of the number of affected

establishments, by industry.

4. Are OSHA's estimates of occupational and job turnover rates

reasonable? If not, please provide estimates of turnover rates for each

of the affected industries.

5. Under what conditions would social work, social welfare

services, teaching, law enforcement or legal services need to be

provided to individuals identified as having suspected or confirmed

infectious TB? What, if any, procedures could not be postponed until

such individuals are determined to be noninfectious? How many workers

in each of these categories may need to have contact with individuals

with suspected or confirmed infectious TB under these conditions?

6. Using the proposed definition of ``suspected infectious TB,''

how many individuals with suspected infectious TB are likely to be

encountered for every confirmed infectious TB case in each of the

covered industries?

7. Are OSHA's estimates of the average number of suspected or

confirmed infectious TB cases that would be transferred, per

establishment in each industry, reasonable? If not, on average, how

many TB cases per facility in each of the affected industries would be

transferred?

8. How are individuals with suspected infectious TB transferred to

establishments with AFB isolation facilities? Who pays for the

transport of such cases, particularly for individuals transferred from

homeless shelters? OSHA solicits comment on the feasibility of

temporary AFB isolation facilities in homeless shelters and on methods

that could be used to temporarily isolate individuals with suspected or

confirmed infectious TB in homeless shelters.

9. Of the suspected infectious TB cases referred to hospitals from

other facilities, how many are immediately ruled out without needing to

be isolated?

10. Are OSHA's estimates of the number of necessary AFB isolation

rooms reasonable? Are existing AFB isolation rooms reasonably

accessible to facilities that transfer individuals with suspected or

confirmed infectious TB?

11. What types of respirators are currently being used to protect

workers against occupational exposure to M. tuberculosis?

12. Which of the NIOSH-approved N95 respirators meet all of the

proposed criteria, including fit testing and fit checking criteria?

13. Are OSHA's estimates of respirator usage rates reasonable? For

each of the covered industries, how often could respirators meeting the

proposed requirements be reused and still maintain proper working

condition? How often, on average, would respirators need to be

replaced? Please specify the type of respirator.

14. OSHA has assumed, in its Preliminary Economic Analysis, that

hospitals will have licensed health care professionals on-site to

perform the medical procedures that would be required by the proposed

rule, and that in the other industries, employees will have to travel

off-site to receive the medical procedures. Which of the other affected

industries typically have licensed health care professionals on site

who could perform the required medical procedures? If employers were

allowed two weeks to provide the medical procedures, rather than being

required to provide them prior to initial assignment to jobs with

occupational exposure, will it be less likely that employees will have

to travel off site to receive these tests/procedures? What would the

costs be if employees travel off-site for these tests/procedures?

15. Are OSHA's estimates of baseline compliance reasonable? If not,

what types of controls are currently in place to protect workers

against occupational exposure to M. tuberculosis, and what proportion

of facilities in each of the affected industries currently are using

such controls?

16. For facilities that have implemented controls to protect

workers against occupational exposure to M. tuberculosis, how effective

have such controls been in reducing the transmission of TB?

17. OSHA's Initial Regulatory Flexibility Analysis assesses the

impacts of the proposed standard on small entities using the Small

Business Administration's (SBA) size standards.

[[Page 54162]]

In addition, OSHA analyzed the impacts of the proposed standard on

entities employing fewer than 20 workers. Are these definitions

appropriate for the covered industries? If not, how should small

entities be defined for each industry?

18. The SBA defines small government jurisdictions as ``governments

of cities, counties, towns, townships, villages, school districts, or

special districts with populations of less than 50,000.'' OSHA requests

comment on the number of such small government jurisdictions.

19. Some parties have suggested that OSHA should allow the use of

the CDC guidelines as an alternative to the proposed rule. However,

OSHA believes that the CDC guidelines are not written in a regulatory

format that would allow OSHA's Compliance Safety and Health Officers

(CSHOs) to determine whether or not an employer is in compliance with

the Guidelines. Others have suggested that OSHA could judge compliance

with the guidelines by determining the number or rate of skin test

conversions at the employer's facility. OSHA does not believe that

smaller facilities have an adequate population for trends in test

conversions to have any statistical validity. OSHA welcomes suggestions

on any methods of making the CDC guidelines an enforceable alternative

to an OSHA regulation or methods of measuring performance that could be

applied across all types and sizes of facilities.

20. Because of the limited availability of data, OSHA characterized

the risk in many sectors as similar to that in hospitals, and less than

that documented in nursing homes and home health care. OSHA welcomes

industry-specific data on test conversion rates or active case rates.

21. OSHA is unable to determine the effectiveness of specific

elements of an effective infection control program in hospitals. OSHA

welcomes any evidence on the relative effectiveness of individual

elements in such programs, such as the identification and isolation of

suspect cases, the use of engineering controls, the use of respirators,

and employee training.

22. OSHA based its estimate of the effectiveness of infection

control programs in other sectors on studies of the effectiveness of

such programs in hospitals. OSHA welcomes any data concerning the

effectiveness of OSHA's proposed infection prevention measures, or of

other alternative infection control measures, in sectors other than

hospitals.

23. SBREFA Panel members suggested a number of alternative

approaches to the regulation. OSHA believes that it has at least

partially adopted a number of these approaches. OSHA welcomes comments

and suggestions on these approaches and the extent to which OSHA should

further adopt them:

Cooperative initiatives, such as expanding OSHA's current

cooperative initiative with JCAHO;

A federal-state government public health partnership to

develop guidelines in various industry sectors;

Performance standards developed with the assistance of

federal, state, and local government, and labor and industry

stakeholders;

Separate approaches for the health and non-health

industries (the approach for the health industries could be keyed to

existing industry standards and that for non-health industries to

guidelines);

Different levels of compliance requirements for different

industries, depending on their expertise, resources, and risk;

Less stringent trigger mechanisms for the more burdensome

portions of the standard; and

Separate standards for each affected industry.

24. OSHA is proposing to include homeless shelters in the Scope of

the standard. During the informal public hearings, OSHA intends to

schedule a special session for participants to present additional

information on homeless shelters. Also, OSHA is conducting a special

study of the homeless shelter sector. The information gathered in the

study will be placed in the docket for public comment. OSHA welcomes

comment on any of the topics this study will cover including:

Percentage of homeless persons that would meet OSHA's

definition of a suspected infectious TB case (A breakdown of which

symptoms are particularly common will help OSHA construct the best

definition);

Turnover among the homeless who use shelters;

Employee turnover in homeless shelters;

Trends in the number of homeless persons served in

shelters.

Criteria currently used by some homeless shelters to

identify suspected infectious TB cases;

Current practices used in homeless shelters to address TB

hazards so that baseline compliance with the proposed standard can be

determined. Of particular concern to OSHA are:

--Methods of isolation; and

--How suspected TB cases are handled.

Feasibility of hospitals providing cards to the homeless

indicating TB skin test status;

Number of TB skin test conversions and active cases among

the homeless and homeless shelter employees;

Types of benefits offered to homeless shelter employees

(e.g., health insurance);

Economic feasibility:

--Costs of running a shelter;

--Revenue sources;

--How costs are accommodated as the number of homeless persons served

increases; and

--Opportunities for cost pass-through;

Number, location and types (e.g., family-oriented, walk-

in, all-male) of homeless shelters;

Number or proportion of homeless shelter workers who are

unpaid volunteers; and

The OSH Act applies to employees, not bona fide

volunteers. However, OSHA understands that some states may, as a matter

of law, require facilities to provide volunteers with protections

established by OSHA standards. OSHA is seeking information on:

--Economic impacts in such states of covering volunteers (e.g., how

costs would be handled, cost pass-through); and

--Protections currently offered to volunteers.

25. In what states, if any, do employers provide volunteers in the

sectors affected by this proposed standard with the same protections as

they provide to employees? How many volunteers might be affected by

such requirements?

26. OSHA is concerned that medical removal protection and medical

treatment of active cases of TB may have significant economic impacts

on small firms that have an employee with an active case of TB. Is

there any form of insurance available for covering the costs of medical

removal protection or medical treatments required by the OSHA standard?

Should OSHA consider phasing-in these provisions of the standard?

27. OSHA believes that substance abuse treatment centers,

particularly in-patient treatment centers, normally have entry

procedures that may include medical examinations. OSHA solicits

comments on entry procedures for substance abuse treatment programs,

the extent to which these entry procedures now include medical

examinations, and the extent to which these examinations now include

and examination for TB symptoms.

28. OSHA requests comment on the effects of extended compliance

phase-in dates for the proposed requirements,

[[Page 54163]]

particularly for respirators, for small businesses and facilities

relying on charitable and/or Medicare and Medicaid funding.

29. OSHA requests comment on all assumptions and estimates used in

developing the Preliminary Economic Analysis. Please provide reasons

and data to support suggested changes to the assumptions and estimates.

30. The World Health Organization (WHO) has launched an initiative

to reduce active TB through the use of multi-drug therapy and using

directly observed therapy. OSHA solicits comment on whether it should

revise its risk assessment or any of its benefits estimates as a result

of this initiative.

31. OSHA requests comment on the number of affected facilities that

are tribally-operated, by industry.

General

1. A number of provisions in the proposed standard are triggered by

the identification of an individual as having either ``suspected

infectious tuberculosis'' or ``confirmed infectious tuberculosis.'' Of

these provisions, are there some that should be triggered only once an

individual has been identified as having ``confirmed infectious

tuberculosis?'' If so, which provisions and why?

2. A number of the proposed standard's provisions require

compliance or performance on an annual basis, e.g., reviews of the

exposure control plan, the biosafety manual for laboratories, and the

respiratory protection program; certification of biological safety

cabinets; fit testing or a determination of the need for fit testing of

respirators; medical histories, TB skin tests; and training. In

addition, certain requirements must be performed on a semi-annual

basis, e.g., inspection and performance monitoring of engineering

controls, verification of air flow direction in laboratories, and, in

some instances, TB skin testing. How can OSHA reduce the aggregate

burden of these requirements, particularly in small entities, while

still providing equal protection to employees? Of these annual and

semi-annual provisions, which, if any, should be performed less

frequently? Why and at what frequency? Which of these provisions, if

any, should be performed more frequently? Why and at what frequency?

Scope

1. Is there information demonstrating risk of TB transmission for

employees in work settings other than those included in the scope?

Should OSHA, for example, expand the scope of this standard to cover

all or some offices of general practitioners or dentists and if so,

how? Should OSHA expand the scope to cover all teachers?

2. Are there provisions of the standard with which emergency

medical services, home health care, and home-based hospice care

employers cannot comply because their employees are at temporary work

settings over which the employer has little or no control? If so, what

are those provisions and why would an employer be unable to comply with

them?

3. In covering only long-term care facilities for the elderly, is

OSHA excluding similar facilities where there is increased risk of

transmission of TB? If so, what are these facilities? Should OSHA

include long-term care populations in addition to the elderly, such as

long-term psychiatric care facilities? If so, what are these

populations?

4. OSHA is proposing that employers provide medical management and

follow-up for their employees who work in covered work settings, but

who are not occupationally exposed, when they have an exposure incident

resulting from an engineering control failure or similar workplace

exposure. Is this the best way of assuring such employees receive

medical management and follow-up?

5. OSHA is covering employees who have occupational exposure in

covered work settings yet are not employees of the work setting (e.g.,

physician employed by another employer with hospital privileges, who is

caring for a TB patient in the hospital). Can this be made more clear?

6. OSHA has proposed that facilities offering treatment for drug

abuse be covered in the scope of the standard. Is coverage of such

facilities appropriate? What factors unique to facilities that offer

treatment for drug abuse would make compliance with the provisions of

this proposed standard infeasible (e.g., would complying with certain

provisions of the standard compromise the provision of services at

facilities that offer treatment for drug abuse)?

Application

1. OSHA has proposed that an employer covered under the standard

(other than an operator of a laboratory) may claim reduced

responsibilities if he or she can demonstrate that his or her facility

or work setting: (1) Does not admit or provide medical services to

individuals with suspected or confirmed infectious TB; (2) has had no

case of confirmed infectious TB in the past 12 months; and (3) is

located in a county that, in the past 2 years, has had 0 cases of

confirmed infectious TB reported in one year and fewer than 6 cases of

confirmed infectious TB reported in the other year. Are there

alternative methods that can be used to assure protection of employees

in areas where infectious TB has not recently been encountered?

Exposure Control Plan

1. OSHA has proposed that the employer's exposure control plan

contain certain policies and procedures. What, if any, policies and

procedures should be added to the plan?

2. The proposed standard requires exposure incidents and skin

conversions to be investigated, but does not require aggregate data

regarding employee conversions to be collected and analyzed. Would the

collection and analysis of aggregate data provide benefits beyond those

provided by investigating each individual exposure incident or

conversion? Why or why not? If aggregate data collection and analysis

were required, what type of analysis should be required, at what

analytical endpoint should employer action be required, and what should

that action be?

3. OSHA has set forth the extent of responsibility for transfer of

individuals based upon the type of work setting where such individuals

are encountered. What are current practices regarding transfer of

individuals with suspected or confirmed infectious TB in the work

settings covered by the proposal?

Work Practices and Engineering Controls

1. Is OSHA's time limit of 5 hours following identification for

transferring an individual with suspected or confirmed infectious TB to

another facility or placing the individual into AFB isolation

appropriate? If not, what is the maximum amount of time that an

individual should be permitted to await transfer or isolation in a

facility before the employer must implement the other provisions of the

proposed standard?

2. OSHA has considered requiring facilities that encounter 6 or

more individuals with confirmed infectious TB within the past 12 months

to provide engineering controls in intake areas where early

identification procedures are performed (e.g., emergency departments,

admitting areas). Should this be a requirement? Are there types of

controls, engineering or otherwise, that would be effective in

controlling transmission in intake areas? Would the trigger of 6

individuals with confirmed infectious TB be appropriate?

[[Page 54164]]

3. Are there methods other than smoke trail testing and continuous

monitors that would be effective for verifying negative pressure in AFB

isolation rooms or areas?

4. OSHA is requiring engineering controls to be inspected and

performance monitored every 6 months. Is this frequency appropriate?

5. OSHA is allowing exhaust air from AFB isolation rooms or areas

where M. tuberculosis may be aerosolized that cannot feasibly be

discharged directly outside to be HEPA-filtered and recirculated back

into general ventilation. Is permitting such recirculation appropriate?

If used, should there be any requirements to detect system failure?

6. OSHA is permitting stand-alone HEPA filter units to be used as a

primary control measure. Is this appropriate? What, if any, methods

other than ventilation and filtration can provide consistent

protection?

7. Should ambulances that have carried an individual with suspected

or confirmed infectious TB be required to be ventilated for a specific

period of time or in a particular way before allowing employees to

enter without a respirator? What engineering controls are available for

ambulances?

Laboratories

1. The standard does not require labeling of laboratory specimens.

Should OSHA require that laboratory specimens be labeled within the

facility or when specimens are being shipped? If so, what should the

label contain? Are there other agencies that require these specimens be

labeled? What are these agencies and what is required?

2. OSHA has attempted to incorporate the CDC/NIH recommendations

given in ``Biosafety in Microbiological and Biomedical Laboratories''

into the standard. Do any provisions need to be added in order for

employees in clinical and research laboratories to be fully protected

against exposures to M. tuberculosis?

Respirators

1. OSHA is requiring employees who are transporting an unmasked

individual with suspected or confirmed infectious TB within a facility

to wear a respirator. Is this appropriate? How often would an

individual with suspected or confirmed infectious TB be transported

unmasked through a facility? Under what circumstances would it be

infeasible to mask such an individual? What other precautions should be

taken when transporting such an individual who is not masked?

2. OSHA is requiring that maintenance personnel use respiratory

protection during maintenance of air systems or equipment that may

reasonably be anticipated to contain aerosolized M. tuberculosis. When

would it be necessary to access such an air system at the time it was

carrying air that may contain aerosolized M. tuberculosis? Should OSHA

require that such air systems be purged and shut down whenever these

systems are accessed for maintenance or other procedures?

3. OSHA has received information that the use of certain kinds of

respirators in helicopters providing emergency medical services may

hamper pilot communication. Have other air ambulance services

encountered this problem? Does this problem exist when the employee is

using a type N95 respirator or other types of respiratory protection

such as powered air purifying respirators? What other infection control

or industrial hygiene practices could be implemented to minimize

employee exposure in these circumstances?

4. The CDC states that there may be selected settings and

circumstances (e.g., bronchoscopy on an individual with suspected or

confirmed infectious TB or an autopsy on a deceased individual

suspected of having had active TB at the time of death) where the risk

of transmission may be such that increased respiratory protection such

as that provided by a more protective negative-pressure respirator or a

powered air purifying respirator may be necessary. Are there

circumstances where OSHA should require use of a respirator that is

more protective than a type N95 respirator? If so, what are the

circumstances and what type of respiratory protection should be

required?

5. OSHA is proposing that respirators be fit-tested annually, which

is consistent with general industrial hygiene practice, or, in lieu of

an annual fit test, that employees have their need to receive the

annual fit test be evaluated by the physician or other licensed health

care professional, as appropriate. For the circumstances and conditions

regulated by this standard, will the evaluation provide enough ongoing

information about the fit of a respirator to be an adequate substitute

for fit testing? Should OSHA require that an actual fit test be

performed periodically? If so, at what frequency?

6. OSHA has not included any provisions regarding the use of

supplied air respirators. Are there circumstances in which supplied air

respirators would be used to protect against M. tuberculosis? Should

OSHA include provisions addressing supplied air respirators in the

standard?

7. OSHA is permitting the reuse of disposable respirators provided

the respirator does not exhibit excessive resistance, physical damage,

or any other condition that renders it unsuitable for use. Will the

respirators continue to protect employees throughout the reuse period?

8. In the proposed standard for TB, OSHA has included separate

provisions for all aspects of a respiratory protection program for

tuberculosis. What other elements might need to be included? Which

respiratory protection provisions, if any, are not appropriate for

protection against TB? Please provide reasons and data to support

inclusion or exclusion of particular provisions.

Medical Surveillance

1. Should any provisions be added to the Medical Surveillance

program?

2. OSHA has not required that physical exams be included as part of

the baseline evaluation. Is there information that is essential to

medical surveillance for TB that can only be learned from a baseline

physical exam?

3. OSHA is specifying tuberculin skin testing frequencies for

employees with negative skin tests. Should tuberculin skin testing be

administered more or less frequently? Are there other ways to determine

the frequency of tuberculin skin testing?

4. OSHA is proposing that employees entering AFB isolation rooms or

areas be skin tested every 6 months. However, employees providing home

health care, home care, and home-based hospice care are to be skin

tested annually. Employees entering the home of an individual who has

suspected or confirmed infectious TB may have the same potential for

exposure to aerosolized M. tuberculosis as employees who enter an

isolation room. In light of this, should employees providing care to

individuals with suspected or confirmed infectious TB in private homes

be skin tested every 6 months?

5. OSHA is requiring that all tuberculin skin testing be

administered, read, and interpreted by or under the supervision of a

physician or other licensed health care professional, as appropriate,

according to current CDC recommendations. Should OSHA require specific

training for individuals who are administering, reading, and

interpreting tuberculin skin tests? If so, what type of training should

be required?

[[Page 54165]]

6. Should OSHA require a declination form for employees who do not

wish to undergo tuberculin skin testing?

7. OSHA is including Medical Removal Protection (MRP) provisions

for employees who are unable to wear respiratory protection or who

contract infectious tuberculosis. Are there additional provisions that

need to be included? What remedies are available to employees in states

where worker compensation system do not consider occupational TB a

compensable disease? What benefits are provided to workers who are

unable to wear a respirator?

8. OSHA is requiring that employees who must wear a respirator be

provided a face-to-face determination of their ability to wear the

respirator. Does this determination need to be made through a medical

evaluation or would the use of an appropriately designed questionnaire

be adequate? What would be the advantages and disadvantages of relying

on a questionnaire to make this determination? Are there sample

questionnaires that have proven to be effective for determining an

employee's ability to wear a respirator?

9. OSHA has drafted Medical Surveillance, paragraph (g), to explain

first who must be provided with the protections listed in the paragraph

and how the surveillance is to be administered and secondly, in

paragraphs (g)(2), Explanation of Terms, and (g)(3), Application, how

the general medical terms are to be construed to meet the standard and

in what instances the medical examinations or tests are to be offered.

The Agency realizes that there is some repetition in these paragraphs

and seeks comment on whether there might be a better way to list the

requirements.

Communication of Hazards and Training

1. OSHA is requiring that signs for isolation rooms and areas bear

a ``STOP'' Sign and the legend ``No Admittance Without Wearing A Type

N95 or More Protective Respirator.'' Is there another sign that would

assure patient confidentiality while providing adequate notification of

the hazard and the necessary steps to minimize the hazard for employees

who may be inadvertently exposed?

2. OSHA is requiring that ducts be labeled ``Contaminated Air--

Respiratory Protection Required.'' Should OSHA require that duct labels

also include the ``STOP'' sign?

3. Is the labeling of ducts carrying air that may contain

aerosolized M. tuberculosis (e.g., from isolation rooms and areas,

labs) at all access points feasible? What, if any, equally protective

alternative exists to permanent labeling in situations where an exhaust

duct from a room may or may not be carrying air containing aerosolized

M. tuberculosis (e.g., the exhaust duct would only be carrying

aerosolized M. tuberculosis when an individual with infectious TB is

being isolated in the room)?

Dates

1. OSHA has proposed that very small businesses with fewer than 20

employees be given an additional 3 months to comply with the standard's

engineering control provisions (i.e., the start-up date for engineering

controls for small businesses would be 270 days from the Effective Date

of the standard). Are there other requirements of the proposed standard

(e.g., respiratory protection) for which very small businesses should

be given additional time to come into compliance? If so, for which

provisions would they need additional time and why? Are 20 employees an

appropriate cut-off for this purpose? Are there other employers that

may need extended time to achieve compliance?

Definitions

1. A number of provisions in the standard are triggered by the

identification of an individual as having ``suspected infectious

tuberculosis.'' Under the definition of ``suspected infectious

tuberculosis'', OSHA has proposed criteria that the Agency believes are

the minimum indicators that, when satisfied by an individual, require

an employer to consider that the individual may have infectious

tuberculosis. Are there other criteria that should be included in this

definition?

2. Coverage of an employee under the standard is based upon the

definition of ``occupational exposure.'' Similar to OSHA's Bloodborne

Pathogens standard, occupational exposure is dependent upon reasonable

anticipation of contact with an individual with suspected or confirmed

infectious tuberculosis or with air that may contain aerosolized M.

tuberculosis. Are there additions that could be made to this definition

that would help employers determine which of their employees are

occupationally exposed?

3. OSHA has proposed requirements for research laboratories that

differ from those of clinical laboratories. The standard includes

definitions of ``research laboratory'' and ``clinical laboratory'' to

assist the employer in differentiating between these two types of

laboratory. Do the definitions clearly differentiate between these two

types of laboratories? Should such a distinction be made? Are there any

modifications that should be made to these definitions?

B. Information Collection Requirements

This proposed Tuberculosis standard contains collections of

information that are subject to review by the Office of Management and

Budget (OMB) under the Paperwork Reduction Act of 1995 (PRA'95), 44

U.S.C. 3501 et seq. and the regulation at 5 CFR Sec. 1320. PRA'95

defines collection of information to mean, ``the obtaining, causing to

be obtained, soliciting, or requiring the disclosure to third parties

or the public of facts or opinions by or for an agency regardless of

form or format.'' [44 U.S.C. Sec. 3502(3)(A)].

The title, description of the need for and proposed use of the

information, summary of the collections of information, description of

the respondents, and frequency of response of the information

collection are described below with an estimate of the annual cost and

reporting burden, as required by 5 CFR Sec. 1320.5(a)(1)(iv) and

Sec. 1320.8(d)(2). Included in the estimate is the time for reviewing

instructions, gathering and maintaining the data needed, and completing

and reviewing the collection of information.

OSHA invites comments on whether the proposed collection of

information:

(1) Ensures that the collection of information is necessary for the

proper performance of the functions of the agency, including whether

the information will have practical utility;

(2) Estimates the projected burden accurately, including whether

the methodology and assumptions used are valid;

(3) Enhances the quality, utility, and clarity of the information

to be collected; and

(4) Minimizes the burden of the collection of information on those

who are to respond, including through the use of appropriate automated,

electronic, mechanical, or other technological collection techniques or

other forms of information technology, e.g., permitting electronic

submissions of responses.

Title: Tuberculosis 29 CFR 1910.1035.

Description: The proposed Tuberculosis (TB) Standard is an

occupational safety and health standard that will prevent or minimize

occupational exposure to TB. The standard's information collection

requirements are essential components that will protect employees from

occupational exposure. The information will be used by employers and

employees to implement the protection

[[Page 54166]]

required by the standard. OSHA compliance officers will use some of the

information in their enforcement of the standard.

Respondents: The respondents are employers whose employees may have

occupational exposure in the following settings: hospitals; long-term

care facilities for the elderly; correctional facilities and other

facilities that house inmates or detainees; hospices; shelters for the

homeless; facilities that offer treatment for drug abuse; facilities

where high hazard procedures are performed; and laboratories that

handle specimens that may contain M. tuberculosis or process or

maintain the resulting cultures, or perform related activity that may

result in the aerosolization of M. tuberculosis.

Also, occupational exposure occurring during the provision of

social work, social welfare services, teaching, law enforcement or

legal services would be covered if the services are provided in the

work settings previously mentioned, or in residences, to individuals

who are in AFB isolation or are segregated or otherwise confined due to

having suspected or confirmed infectious TB. Respondents also include

employers whose employees are occupationally exposed during the

provision of emergency medical services, home health care and home-

based hospice care. Approximately 101,875 employers will be responding

to the standard.

Total Estimated Cost: First year $62,972,210; Recurring years

$53,691,915.

Summary of the Collection of Information

----------------------------------------------------------------------------------------------------------------

Total

Information collection Number of Frequency of response Average time per burden

requirement responses response\1\ (hours)

----------------------------------------------------------------------------------------------------------------

Exposure Control Plan:

(c)(2)(i).................... 101,875 All Affected Employers to 24 hours per 906,980

Develop Plan. Hospital.

8 hours per

Facility for all Other

Industries

(c)(2)(vii)(B)............... 101,875 Annual Reviews and 8 hours per 238,243

Updates for All Affected Hospital.

Employers. 2 hours per

Facility for all Other

Industries

Respiratory Protection:

(f)(2)....................... 82,138 All Employers not 8 hours per 335,323

Qualified for Appendix A Hospital.

Program to Develop 4 hours per

Program. Facility for all Other

Industries

(f)(5), Appendix B........... 2,207,580 Initially, for all 30 minutes per 551,962

employees assigned employee.

respirators.

22,078 Annual refit tests for 1% 30 minutes per 5,520

of population assigned employee.

respirators.

(f)(8)....................... 82,138 Annual Evaluation of 2 hours per 83,831

Program for All Affected Hospital.

Employers not Qualified 1 hour per

for Appendix A Program. Facility for all Other

Industries

Medical Surveillance:

Medical History 1,831,724 Initially for All 1 hour per 1,831,724

(g)(3)(i)(A). Affected Employees. Hospital Employee (inc.

LHCP time).

1 hour per

Employee in all Other

Industries (inc. travel

time)

1,595,432 Annually for All Affected 1 hour per 1,595,432

Employees in Facilities Hospital Employee (inc.

not Qualified for LHCP time).

Appendix A. 1 hour per

Employee in all Other

Industries (inc. travel

time)

47,953 Initially, for New 1 hour per 47,953

Employees. Hospital Employee (inc.

LHCP time).

1 hour per

Employee in all Other

Industries (inc. travel

time)

Medical Examination 47,863 Annually, 3% of 2 hours per 72,518

(inc. History and Physical) Controlled Population at Hospital Employee in

(g)(3)(i) (B)-(D). Risk estimated to Facilities not

request exam as a result Qualified for Appendix

of having signs or A (inc. LHCP time).

symptoms of TB; have a 1\1/2\ hour per

TST conversion; or Employee in All Other

indicated as a result of Industries (inc. travel

an exposure incident. time)

Tuberculin Skin

Tests

Initial 2-Step TST 474,627 Initially, for Entire 1\1/2\ hours 1,026,377

(g)(3)(i)(A). Controlled Population at per Hospital Employee

Risk. (inc. LHCP time).

2\1/4\ hour per

Employee in All Other

Industries (inc. travel

time)

Exposure Incident 8,268 Annually, 2% of 1\1/2\ hours 17,879

(g)(3)(i)(C). Controlled Population at per Hospital Employee

Risk in Facilities (inc. LHCP time).

Qualified for Appendix A. 2\1/4\ hour per

Employee in All Other

Industries (inc. travel

time)

Pre-Exit (g)(3)(i)(E).... 76,257 Annually for Employment 1 hour for each 110,504

Turnover. Hospital Employee (inc.

LHCP time).

1\1/2\ hour per

Employee in All Other

Industries (inc. travel

time)

Prior to Initial 76,257 All New Employees with 1\1/2\ hour per 165,756

Assignment. Occupational Exposure. Hospital Employee (inc.

LHCP time).

[[Page 54167]]

Annual (g)(3)(ii)(A)..... 413,400 All employees in \1/2\ hour per 297,991

facilities not qualified Hospital Employee (inc.

for Appendix A. LHCP time).

45 minutes per

Employee in all Other

Industries (inc. travel

time)

Additional 6-month TST 131,367 All employees who: 1 hour per 171,314

(g)(3)(iii). Enter an AFB Hospital Employee (inc.

isolation room or area LHCP time).

Perform or are 1\1/2\ hour for

present during the each Employee in All

performance of high- Other Industries (inc.

hazard procedures travel time)

Transport or are

present during the

transport of an

individual with

suspected or confirmed

infectious TB in an

enclosed vehicle

Work in an

intake area in

facilities where 6 or

more confirmed TB cases

have been encountered in

the past 12 mos

Information Provided 1,965,967 Information for each 10 minutes per 327,661

to Licenced Health Care affected establishment employee.

Professional (LHCP) to provide a copy of the

(g)(6)(I). rule, and for

information on each

employee with a

respirator.

558,549 Information for each new 10 minutes per 93,091

employee assigned a employee.

respirator.

64,692 Information surrounding 10 minutes per 10,782

exposure incidents (2% employee.

of controlled population

at risk).

LHCP Written Opinion 2,745,188 Initially, for each 5 minutes per 228,766

(g)(7). medical procedure written opinion.

performed.

2,034,269 Annually, for each 5 minutes per 169,522

medical procedure written opinion.

performed.

Training:

(h)(3)(ii)(B)................ 202,066 Number of training 2 hours for 237,829

sessions in first year. employees required to

wear respirators.

1 hour for

employees with

occupational exposure

who are not assigned

respirators

Assumes 20

employees per session

(h)(3)(ii)(A)................ 106,258 Number of training For new 50,193

sessions for new employees:.

employees entering 2 hours for employees

affected occupations for required to wear

the first time + number respirators

of training sessions for 1 hour for employees

employees staying in with occupational

affected occupations, exposure who are not

but starting new jobs. assigned respirators

\1/2\ hours for

employees required to

wear respirators

15 minutes for employees

with occupational

exposure who are not

assigned respirators

(h)(3)(ii)(C)................ 154,966 Recurring number of For 25% of 57,313

training sessions. exposed employees

unable to demonstrate

competence:.

1 hour for employees

required to wear

respirators

\1/2\ hour for employees

with occupational

exposure who are not

assigned respirators

For 75% of

exposed employees able

to demonstrate

competence

Assumes 20

employees per session

Recordkeeping:

Medical (I)(1)(I)............ 3,713,645 Initially, to create a 10 minutes to 631,320

medical record for each set up each record.

affected employee.

1,358,800 Create medical records 10 minutes to 230,996

for each new employee set up each record.

with occupational

exposure.

2,447,669 Annually, for each 5 minutes to 195,814

medical procedure update each record.

performed.

[[Page 54168]]

Training (I)(3)(I)........... 264,451 Initially, to create 10 minutes to 44,957

records for each create each training

training session. record.

217,351 Annually, to reflect 10 minutes to 36,950

recurring training create each training

sessions and initial record.

training for new

employees.

Engineering controls 24,761 Annually, for each 5 minutes per 3,962

(I)(4)(I). engineering control. record.

Availability (I)(5).......... 2,037 Annually, for 2% of 5 minutes per 163

affected employers. employer.

Transfer to NIOSH............ 1 Annually, for estimated 1 1 hour per 1

employer per year to employer.

transfer records.

------------- ------------

Totals...................

First-Year.. ........... ......................... ........................ 7,098,011

Recurring... ........... ......................... ........................ 3,655,728

----------------------------------------------------------------------------------------------------------------

\1\ Estimates represent average burden hours per response. The actual burden hours per response will vary

depending on factors such as the size of the facility, current practices at the facility, and whether the

facility transfers or admits individuals with suspected or confirmed infectious TB.

Note: Estimates take into account baseline compliance with the proposed requirements.

The Agency has submitted a copy of the information collection

request to OMB for its review and approval. Interested parties are

requested to send comments regarding this information collection to the

Office of Information and Regulatory Affairs, Attn. OSHA Desk Officer,

OMB New Executive Office Building, 725 17th Street NW, Room 10235,

Washington DC 20503.

Comments submitted in response to this notice will be summarized

and/or included in the request for Office of Management and Budget

approval of the final information collection request: they will also

become a matter of public record.

Copies of the referenced information collection request are

available for inspection and copying in the OSHA Docket Office and will

be mailed immediately to any person who request copies by telephoning

Todd Owen at (202) 219-7075. For electronic copies of the Tuberculosis

information collection request, contact the Labor News Bulletin Board

(202) 219-4784, or OSHA web page on the Internet at http://

www.osha.gov/. Copies of the information collection requests are also

available at the OMB docket office.

C. Federalism

This standard has been reviewed in accordance with Executive Order

12612, 52 FR 41685 (October 30, 1987), regarding Federalism. This Order

requires that agencies, to the extent possible, refrain from limiting

State policy options, consult with States prior to taking any actions

that would restrict State policy options, and take such actions only

when there is clear constitutional authority and the presence of a

problem of national scope. The Order provides for preemption of State

law only if there is a clear Congressional intent for the Agency to do

so. Any such preemption is to be limited to the extent possible.

Throughout the development of this proposed standard, OSHA has

sought and received assistance from state representatives.

Representatives of state departments of health and labor and industries

have helped direct OSHA to pertinent information and studies on TB and

have submitted drafts of state standards relevant to TB. In addition,

representatives of state occupational safety and health departments

participated in the review of the draft standard by OSHA field offices

and in OSHA's TB Stakeholder meetings, where the requirements of the

proposed standard were presented and information was collected from

employers, employees, and their representatives on what was being done

to prevent occupational exposure to TB in the various worksites and how

an OSHA standard for TB could further reduce the exposures.

Section 18 of the Occupational Safety and Health Act (OSH Act),

expresses Congress' clear intent to preempt State laws with respect to

which Federal OSHA has promulgated occupational safety or health

standards. Under the OSH Act a State can avoid preemption only if it

submits, and obtains Federal approval of, a plan for the development of

such standards and their enforcement. Occupational safety and health

standards developed by such State-Plan states must, among other things,

be at least as effective in providing safe and healthful employment and

places of employment as the Federal standards.

The proposed tuberculosis standard is drafted so that employees in

every State will be protected by general, performance-oriented

standards. To the extent that there are State or regional

peculiarities, States with occupational safety and health plans

approved under Section 18 of the OSH Act would be able to develop their

own State standards to deal with any special problems. Moreover, the

performance nature of this standard, of and by itself, allows for

flexibility by States and employers to provide as much safety as

possible using varying methods consonant with conditions in each State.

There is a clear national problem related to occupational safety

and health for employees exposed to M. tuberculosis. Approximately 6.5%

of the U.S. adult population is infected (i.e., carrying the

tuberculosis bacillus, not manifesting active disease), and although

the prevalence of TB infection and disease varies throughout the

country, TB disease has been reported in every state. Political and

geographic boundaries do not contain infection and disease spread. The

U.S. population is mobile, moving freely from place to place for

business and pleasure. Immigrants, a group whose members are known to

have a high prevalence of TB, settle throughout the country. While

there are counties that do not report cases in a given year, the

counties change from year to year along with the number of cases

reported. In addition, reports do not always reflect all the locations

where exposure incidents can occur; infectious TB cases are often

transferred from their site of diagnosis to a distant location for

treatment and reported as a TB case only in the county

[[Page 54169]]

where treatment is administered. Finally, underreporting may occur

because some individuals with infectious TB, in particular the homeless

and clients of drug abuse facilities, do not avail themselves of

further diagnosis and treatment. TB infection and disease is truly

national in scope.

Those States which have elected to participate under Section 18 of

the OSH Act would not be preempted by this regulation and would be able

to deal with special, local conditions within the framework provided by

this performance-oriented standard while ensuring that their standards

are at least as effective as the Federal standard.

D. State Plans

The 23 States and 2 territories with their own OSHA-approved

occupational safety and health plans must adopt a comparable standard

within 6 months after the publication of a final standard for

occupational exposure to tuberculosis or amend their existing standard

if it is not ``at least as effective'' as the final Federal standard.

OSHA anticipates that this standard will have a substantial impact on

state and local employees. The states and territories with occupational

safety and health state plans are: Alaska, Arizona, California,

Connecticut, Hawaii, Indiana, Iowa, Kentucky, Maryland, Michigan,

Minnesota, Nevada, New Mexico, New York, North Carolina, Oregon, Puerto

Rico, South Carolina, Tennessee, Utah, Vermont, Virginia, the Virgin

Islands, Washington, and Wyoming. (In Connecticut and New York, the

plan covers only State and local government employees). Until such time

as a State standard is promulgated, Federal OSHA will provide interim

enforcement assistance, as appropriate.

II. Pertinent Legal Authority

The purpose of the Occupational Safety and Health Act, 29 U.S.C.

651 et seq. (``the Act'') is ``to assure so far as possible every

working man and woman in the nation safe and healthful working

conditions and to preserve our human resources.'' 29 U.S.C.

Sec. 651(b). To achieve this goal Congress authorized the Secretary of

Labor to promulgate and enforce occupational safety and health

standards. 29 U.S.C. Secs. 655(a) (authorizing summary adoption of

existing consensus and federal standards within two years of Act's

enactment), 655(b) (authorizing promulgation of standards pursuant to

notice and comment), 654(b) (requiring employers to comply with OSHA

standards).

A safety or health standard is a standard ``which requires

conditions, or the adoption or use of one or more practices, means,

methods, operations, or processes, reasonably necessary or appropriate

to provide safe or healthful employment or places of employment.'' 29

U.S.C. Sec. 652(8).

A standard is reasonably necessary or appropriate within the

meaning of Section 652(8) if it substantially reduces or eliminates

significant risk, and is economically feasible, technologically

feasible, cost effective, consistent with prior Agency action or

supported by a reasoned justification for departing from prior Agency

actions, supported by substantial evidence, and is better able to

effectuate the Act's purposes than any national consensus standard it

supersedes. See 58 Fed. Reg. 16612--16616 (March 30, 1993).

OSHA has generally considered, at a minimum, a fatality risk of 1/

1000 over a 45-year working lifetime to be a significant health risk.

See the Benzene standard, Industrial Union Dep't v. American Petroleum

Institute, 448 U.S. 607, 646 (1980); the Asbestos standard,

International Union, UAW v. Pendergrass, 878 F.2d 389, 393 (D.C. Cir.

1989).

A standard is technologically feasible if the protective measures

it requires already exist, can be brought into existence with available

technology, or can be created with technology that can reasonably be

expected to be developed. American Textile Mfrs. Institute v. OSHA, 452

U.S. 490, 513 (1981) (``ATMI''), American Iron and Steel Institute v.

OSHA, 939 F.2d 975, 980 (D.C. Cir. 1991)(``AISI'').

A standard is economically feasible if industry can absorb or pass

on the costs of compliance without threatening its long-term

profitability or competitive structure. See ATMI, 452 U.S. at 530 n.

55; AISI, 939 F.2d at 980.

A standard is cost effective if the protective measures it requires

are the least costly of the available alternatives that achieve the

same level of protection. ATMI, 453 U.S. at 514 n. 32; International

Union, UAW v. OSHA, 37 F.3d 665, 668 (D.C. Cir. 1994) (``LOTO III'').

All standards must be highly protective. See 58 FR 16614--16615;

LOTO III, 37 F.3d at 669. However, health standards must also meet the

``feasibility mandate'' of Section 6(b)(7) of the Act, 29 U.S.C.

Sec. 655(b)(5). Section 6(b)(5) requires OSHA to select ``the most

protective standard consistent with feasibility'' that is needed to

reduce significant risk when regulating health hazards. ATMI, 452 U.S.

at 509.

Section 6(b)(5) also directs OSHA to base health standards on ``the

best available evidence,'' including research, demonstrations, and

experiments. 29 U.S.C. Sec. 655(b)(5). OSHA shall consider ``in

addition to the attainment of the highest degree of health and safety

protection * * * the latest scientific data * * * feasibility and

experience gained under this and other health and safety laws.'' Id.

Section 6(b)(7) authorizes OSHA to include among a standard's

requirements labeling, monitoring, medical testing and other

information gathering and transmittal provisions. 29 U.S.C.

Sec. 655(b)(7).

Finally, whenever practical, standards shall ``be expressed in

terms of objective criteria and of the performance desired.'' Id.

III. Events Leading to the Proposed Standard

Tuberculosis (TB) is a contagious disease caused by the bacterium

Mycobacterium tuberculosis (M. tuberculosis). Infection is usually

acquired by the inhalation of airborne particles carrying the

bacterium. These airborne particles, called droplet nuclei, can be

generated when persons with infectious pulmonary or laryngeal TB cough,

sneeze, or speak. TB has long been considered an occupational hazard in

the health care setting. However, it is inhalation exposure to

aerosolized M. tuberculosis and not some other factor unique to the

health care setting that places workers at risk of infection. Thus, any

work setting where employees can reasonably be anticipated to encounter

individuals with infectious TB also contains the occupational hazard of

TB infection.

On December 21, 1992, the Labor Coalition to Fight TB in the

Workplace (the Coalition) requested the Agency to issue nationwide

enforcement guidelines to protect workers against exposure to TB in

health care, criminal justice, and other high risk settings and to

issue a Joint Advisory Notice on TB in conjunction with the Centers for

Disease Control and Prevention (CDC) (Ex. 2). This petition was signed

by the presidents of the Service Employees International Union (SEIU),

the American Federation of State, County, and Municipal Employees

(AFSCME), and the American Federation of Teachers (AFT), and was

endorsed by 9 other unions. The petition included a list of provisions

that the petitioners felt should be included in the guidelines, ranging

from a written control plan and medical surveillance to anti-

discrimination language and medical removal protection.

[[Page 54170]]

Eight months later, on August 25, 1993, the Coalition petitioned

OSHA to initiate rulemaking for a permanent standard issued under

Sec. 655(b) of the Act to protect workers from occupational

transmission of TB (Ex. 1). Citing the recent resurgence of TB and the

emergence and increasing rate of new cases of multidrug-resistant TB

(MDR-TB), the petitioners stressed the need for a substance-specific

standard to address the hazards associated with occupational exposures

to TB. The petitioners contended that the non-mandatory CDC TB

Guidelines do not provide adequate protection because they are not

fully or rigorously implemented in most workplaces. They also stated

that in every outbreak of TB investigated by CDC, noncompliance with

the Guidelines was evident.

In addition to a permanent standard, the petitioners also requested

that OSHA immediately issue the nationwide enforcement guidelines that

the Coalition had previously requested, and that OSHA promulgate an

Emergency Temporary Standard (ETS) as an interim measure. The Coalition

requested that the standard be applicable to all work settings where

employees can reasonably anticipate contact with infectious TB. The

petition included a discussion on occupational risk that included both

the traditional high-risk occupations and other occupations such as

sheet metal workers, postal workers, airline employees, teachers, and

office workers.

Like the request for nationwide enforcement guidelines, the

petition contained provisions that the petitioners requested be

included in the standard. Examples include a facility hazard assessment

and written exposure control plan, engineering and work practice

controls, respiratory protection, medical surveillance (e.g.,

tuberculin skin testing) and counseling, post-exposure management,

outbreak management, training, and recordkeeping.

On October 8, 1993, OSHA issued nationwide enforcement procedures

for occupational exposure to TB. The compliance document contained the

enforcement procedures that the Agency could and would use in certain

work settings for protecting workers with occupational exposure to TB.

In the compliance procedures, the Agency noted that although OSHA has

no standard designed specifically to reduce occupational exposure to

TB, the Agency has existing standards that apply to this hazard. For

example, 29 CFR 1910.134 requires employers to provide respiratory

protection equipment and 29 CFR 1910.145(f) requires accident

prevention tags to warn of biological hazards. In addition, section

5(a)(1), the General Duty Clause of the Act, requires that each

employer:

* * * furnish to each of his employees employment and a place

of employment which are free from recognized hazards that are

causing or are likely to cause death or serious physical harm to his

employees.

On January 26, 1994, in response to their August 25 petition,

Secretary of Labor Robert B. Reich informed the petitioners that OSHA

was initiating rulemaking on a permanent standard to be issued under

Section 6(b)(5) of the Act for occupational exposure to TB (Ex. 1B). At

the same time, the petitioner's request for an ETS was denied. The

Agency had determined that the available data did not meet the criteria

for an ETS as set forth in Section 6(c) of the Act. However, OSHA

committed to enforcing existing regulations and Section 5(a)(1) of the

Act in certain work settings while preparing this standard.

On October 28, 1994 the CDC issued revised guidelines for

preventing the transmission of tuberculosis in health care facilities

(Ex. 4B). In addition, in June of 1995, the National Institute for

Occupational Safety and Health (NIOSH) published revised certification

procedures for non-powered air purifying particulate respirators (Ex.

7-261). As a result of changes in these two documents, OSHA issued

revised enforcement policies and procedures relative to TB in February

of 1996 (Ex. 7-260).

In October and November of 1995, OSHA held a series of meetings

with stakeholder groups representing labor unions, professional

organizations, trade associations, state and federal government,

representatives of employers, as well as frontline workers from the

various sectors anticipated to be covered by the proposed standard.

During these meetings, participants provided input relative to the

concepts and approaches OSHA was considering for the proposed

tuberculosis standard.

In September of 1996, in accordance with the Small Business

Regulatory Enforcement Fairness Act of 1996 (SBREFA), a Small Business

Advocacy Review Panel was convened to consider the impact of OSHA's

draft proposed tuberculosis standard on affected small entities. The

panel, comprised of members from the Office of Advocacy of the Small

Business Administration (SBA), the Office of Management and Budget

(OMB), and OSHA, prepared a report based on the Panel's findings and

recommendations with regard to comments on the standard received from

small business employers. This report was submitted to the Assistant

Secretary for OSHA for its consideration during the development of the

standard (Ex. 12). OSHA's proposed standard reflects input generated

during both the stakeholder meetings and the SBREFA review process.

Comparison of OSHA's Proposed Standard and CDC's Revised Guidelines

In preparing its proposed standard for TB, OSHA has relied heavily

on the expertise of CDC. The Agency has consulted with CDC and has

incorporated the basic elements of CDC's revised guidelines for

preventing the transmission of M. tuberculosis in health care

facilities in this proposed standard. Both CDC and OSHA rely on

minimizing exposures and consequent transmission by identifying

suspected infectious TB individuals and isolating them. The OSHA

proposed standard includes the following CDC components: written

exposure control plans, procedures for early identification of

individuals with suspected or confirmed infectious TB, procedures for

initiating isolation of individuals with suspected or confirmed

infectious TB or for referring those individuals to facilities with

appropriate isolation capabilities, procedures for investigating

employee skin test conversions, and education and training for

employees. In addition, OSHA has incorporated CDC recommendations for

engineering control measures such as the use of negative pressure for

AFB isolation rooms or areas, daily monitoring of negative pressure

while AFB isolation rooms are in use for TB, HEPA filtration of

recirculated air from AFB isolation rooms, and periodic maintenance and

monitoring of engineering controls. With regard to respiratory

protection, OSHA has adopted CDC's standard performance criteria for

the selection of respiratory protection devices appropriate for use

against M. tuberculosis. And finally, where appropriate, OSHA has

attempted to assure that where certain practices are required by OSHA's

proposed standard, e.g., tuberculin skin testing and medical management

and follow-up of employees who acquire TB infections or active disease,

these practices are conducted according to the current recommendations

of the CDC. Therefore, OSHA's proposed standard for occupational

exposure to TB closely follows CDC's recommended elements for a TB

infection control program.

However, there are some minor differences between OSHA's proposed

standard and CDC's guidelines that go

[[Page 54171]]

beyond the obvious enforcement distinction between a guideline and a

standard. These differences are found primarily in the areas of risk

assessment, medical surveillance and respiratory protection. Even so,

OSHA believes that despite these differences the vast majority of the

provisions included in this proposed standard closely track the

recommendations of the CDC. The following discussion identifies where

these differences occur and describes the extent of these differences

and the degree to which they impact on employers' responsibilities

under the proposed standard.

Risk Assessment

As a part of its guidelines, CDC recommends that a risk assessment

be conducted in all facilities to assess the risk of transmission of M.

tuberculosis in each facility. This risk assessment is to be conducted

using information such as the profile of TB in the community, the

number of suspected and confirmed cases of TB among patients and health

care workers, results of health care worker tuberculin skin testing

(i.e., conversion rates), and observation of TB infection control

practices. Using the results of this risk assessment, appropriate

infection control interventions can then be selected based on the

actual risk in the facility. CDC includes a protocol for conducting

this risk assessment in which there are 5 categories of risk:

``minimal'', ``very-low'', ``low'', ``intermediate'', and ``high''.

Each category from ``minimal'' to ``high'' has an increasing number of

infection control interventions that are recommended for each

particular level of risk.

OSHA, however, has chosen a simpler approach and is not requiring

employers to conduct such a risk assessment. Consistent with other

standards, OSHA has determined that employees in the work settings and

employees providing services set forth in the scope section are at risk

of occupational exposure to TB. Their employers are required to conduct

an exposure assessment to determine which employees have occupational

exposure, i.e., reasonably anticipated contact with an individual with

suspected or confirmed infectious TB or air that may contain

aerosolized M. tuberculosis. The standard then specifies the provisions

applicable for the employees whom the employer has identified as having

occupational exposure. In addition, consistent with its approach in

other standards, OSHA does not require that individual risk assessments

be conducted by each work setting covered under the standard, as they

may be too difficult and burdensome for employers to prepare. Also,

many work settings will have too few occupationally exposed employees

to do an accurate risk assessment. Finally, conducting the risk

assessments in order to determine applicable duties may require a level

of expertise some facilities lack, making enforcement burdensome for

the Agency.

OSHA realizes, however, that in many work settings, very few

individuals with suspected or confirmed infectious TB may be seen and

that in many of those work settings, individuals with suspected or

confirmed infectious TB will be transferred to other facilities that

are better equipped to provide services and care using appropriate TB

isolation precautions. Because there is likely to be less risk of

transmission of M. tuberculosis in those situations, OSHA believes that

it is possible to make the standard less burdensome for the employers

with these types of work settings while still maintaining worker

protection.

For example, an employer who can demonstrate that his or her

facility or work setting: (1) Does not admit or provide medical

services to individuals stwith suspected or confirmed infectious TB,

(2) has not had any individuals with confirmed infectious TB within the

work setting within the last 12 months, and (3) is located in a county

that, in the past 2 years, has had 0 cases of confirmed infectious TB

reported in one year and fewer than 6 cases of confirmed infectious TB

reported in the other year, does not have to comply with all provisions

of the standard. Such employers would only be responsible for

compliance with certain provisions, e.g., a written exposure control

plan, a baseline skin test and medical history, medical management and

follow-up after exposure incidents, medical removal protection where

necessary, employee training, and recordkeeping. These provisions are

very similar to the recommendations of the CDC for facilities

classified as having ``minimal risk,'' i.e., no TB in the community or

in the facility. The only major difference is that CDC does not

recommend baseline skin testing. However, CDC does state that baseline

skin testing would be advisable so that if an unexpected exposure does

occur, conversion could be distinguished from positive skin test

results caused by previous exposures.

Medical Surveillance

In the area of medical surveillance, the main differences between

OSHA and CDC are related to tuberculin skin testing. OSHA requires

baseline skin testing for all employees whom the employer identifies as

having occupational exposure. CDC recommends baseline skin testing for

all employees with potential exposure except those who work in

facilities that fall into CDC's ``minimal risk'' category. However, CDC

notes that even for employees in ``minimal risk'' facilities, it may be

advisable to perform baseline skin testing so that if unexpected

exposures do occur, conversions can be distinguished from positive skin

test results caused by previous exposures. Thus, there is little

difference between OSHA requirements and CDC recommendations with

regard to baseline skin testing.

Relative to periodic skin testing, OSHA requires periodic re-

testing for all employees identified as having occupational exposure

who have negative skin tests except for the employees of those

employers who have no TB in the community and who have not encountered

any individuals with confirmed infectious TB in their work settings

within the past year. CDC recommends re-testing for employees in the

``low'', ``intermediate'', and ``high'' risk categories. According to

the CDC guidelines, periodic re-testing is not necessary for employees

in the ``minimal'' risk category or the ``very-low'' risk categories.

CDC's periodic skin test recommendations for the ``minimal'' risk

category are similar to OSHA's limited program for employers who do not

admit or provide medical services to individuals with suspected or

confirmed infectious TB, have not encountered any confirmed infectious

TB in their work setting, and are located in a county that, in the past

2 years, has reported 0 cases of confirmed infectious TB in one year

and fewer than 6 cases in the other year. OSHA is different from the

CDC in that employees in a ``very-low risk category'' are required to

be periodically retested. However, CDC notes that even in the ``very-

low'' risk category, employees who are involved in the initial

assessment of individuals in emergency departments and admitting areas

may have potential exposure and thus may need periodic re-testing.

Another difference between CDC and OSHA is the frequency of the re-

testing. This is primarily due to the fact that OSHA's required

frequencies are based on the type of work that employees do that result

in exposures whereas CDC's recommendations are based more on evidence

of conversions. For example, OSHA requires re-testing every six months

for all employees who (1) enter AFB isolation rooms or areas, (2)

perform high-hazard procedures, (3)

[[Page 54172]]

transport individuals with suspected or confirmed infectious TB in an

enclosed vehicle, or (4) work in intake areas where early

identification procedures are performed (e.g., emergency departments,

admitting areas) in facilities where 6 or more individuals with

confirmed infectious TB have been encountered in the past 12 months.

For all other employees with occupational exposure, re-testing is

required every 12 months. In comparison, CDC recommends re-testing

every year for employees in ``low'' risk categories, every 6-12 months

for employees in ``intermediate'' risk categories, and every 3 months

for employees in ``high'' risk categories. Under CDC recommendations,

employees in ``low'' risk categories who enter AFB isolation rooms or

areas or employees who transport individuals with suspected or

confirmed infectious TB in an enclosed vehicle would be re-tested every

12 months. However, under OSHA requirements, those same employees would

be required to be re-tested every six months. Thus, OSHA is more

protective than CDC in this case.

OSHA also would require that employees who perform high-hazard

procedures or who work in intake areas where early identification

procedures are performed in facilities that encounter 6 or more

individuals with confirmed infectious TB be re-tested every six months.

Under CDC's Guidelines employees in areas in which cough-inducing

procedures are performed on individuals who may have active TB are

recommended to follow an intermediate risk protocol. Similarly, CDC

recommends that an intermediate risk protocol be followed in areas

where more than six individuals who may have active TB receive initial

assessment and diagnostic evaluation (e.g., ambulatory care, emergency

departments, admitting areas). CDC recommends re-testing every 6-12

months for employees in intermediate risk categories. OSHA would

require re-testing every 6 months for the two situations above, which

is very similar to CDC's recommendation of re-testing every 6-12

months.

CDC is more protective in its recommendations for employees in the

``high'' risk category. These employees are recommended to be re-tested

every 3 months. OSHA does not have a requirement for re-testing

employees every 3 months. However, after an exposure incident, OSHA

requires that a skin test be administered as soon as feasible and again

3 months after the exposure incident, if the first skin test is

negative. Since it is possible that an exposure incident(s) could be

the type of event that would cause an employee(s) to be included in the

``high'' risk category as defined by CDC, OSHA requirements, to some

extent, track the CDC recommendations for a higher frequency of

periodic skin testing.

With regard to two-step testing, both OSHA and CDC require or

recommend two-step testing at the time baseline skin testing is

administered. Also, both OSHA and CDC add that two-step testing is not

necessary if the employee has had a documented negative skin test

within the last 12 months. CDC is different from OSHA in that its

Guidelines imply that two-step testing can be discontinued if there is

evidence of a low frequency of boosting in the facility. OSHA's

proposed standard does not allow such an exemption, i.e., for each

employee who must have a baseline skin test at the time of the initial

medical examination, the skin test must include a two-step test unless

the employee has a documented negative test within the last 12 months,

regardless of the frequency of boosting in the facility. The value of

two-step skin testing is that it enables one to distinguish true

conversions from boosted reactions. OSHA believes that this is

important to know for each employee because if the employee is

incorrectly identified as having converted, he or she may needlessly be

subjected to preventive therapy that may have toxic side effects of its

own. Since it is important to know the true skin test status for each

employee, OSHA has preliminarily concluded that it is inappropriate to

allow the overall frequency of boosting among employees in a facility

to dictate whether any one employee receives two-step testing at the

time of his or her baseline testing.

Respiratory Protection

OSHA requirements and CDC recommendations for respiratory

protection are very similar. A respirator is a personal protective

equipment device worn over the nose and mouth of the employee that

filters certain airborne contaminants from the inhaled air. OSHA has

adopted CDC's performance criteria for respirators appropriate for use

for TB. Also, both OSHA and CDC have similar requirements or

recommendations that respirators be worn when entering an isolation

room, when performing cough-inducing procedures or aerosol-generating

procedures on an individual with suspected or confirmed infectious TB,

when repairing or maintaining air systems that may contain aerosolized

M. tuberculosis, when transporting an individual with suspected or

confirmed infectious TB in an enclosed vehicle and when working in a

residence where an individual with suspected or confirmed infectious TB

is known to be present. However, OSHA also requires that respirators be

worn when employees are transporting individuals with suspected or

confirmed infectious TB within the facility if those individuals are

not masked (e.g., a surgical mask or a valveless respirator). CDC does

not have a similar recommendation for respiratory protection while

transporting individuals within the facility, but CDC does recommend,

and assumes to some extent, that individuals with suspected or

confirmed infectious TB are masked whenever they are outside an

isolation room. In addition, OSHA requires that respirators be worn

when employees work in an area where an unmasked individual with

suspected or confirmed infectious TB has been segregated or otherwise

confined. For example, this provision would cover employees such as

those who work in admitting areas and must attend to unmasked

individuals with suspected or confirmed infectious TB while those

individuals are awaiting transfer. These types of employees are likely

to be found in facilities that would meet CDC's definition of

``minimal'' risk. CDC states that respiratory protection is not

necessary for employees in the ``minimal'' risk category. However,

again, CDC recommends that if an individual with suspected or confirmed

infectious TB is identified in a ``minimal'' risk facility, the

individual should be masked while he or she is awaiting transfer to

another facility, thus obviating the need for respiratory protection.

OSHA, on the other hand, cannot require employers to mask clients or

patients in a facility, and the Agency must therefore include

provisions for respirator use to protect potentially exposed employees.

However, consistent with CDC, OSHA proposes not to require respirators

where the employer elects, as a part of his or her own administrative

policies, to mask individuals with suspected or confirmed infectious

TB. Thus, when individuals with suspected or confirmed infectious TB

are masked while they are awaiting transfer to another facility or

while they are being transported within the facility, employees would

not be required by the standard to wear a respirator.

In some instances, the CDC may be more protective than OSHA with

regard to respiratory protection. The CDC states that the facility's

risk assessment may identify selected settings where the

[[Page 54173]]

estimated risk of transmission of M. tuberculosis may be such that a

level of respiratory protection exceeding the standard performance

criteria is appropriate (e.g., more protective negative pressure

respirators, powered air purifying respirators). The examples given of

such selected settings are a bronchoscopy performed on an individual

suspected of having TB and an autopsy performed on a deceased person

suspected of having had active TB at the time of death. OSHA does not

have a similar requirement for more protective respiratory protection.

Respirators meeting the minimal performance criteria laid out by the

standard would be required by OSHA for employees performing all high-

hazard procedures, including bronchoscopies and aerosol-generating

autopsy procedures.

IV. Health Effects

Introduction

For centuries Tuberculosis (TB) has been responsible for the death

of millions of people throughout the world. It was not until 1882,

however, that Robert Koch identified a species of bacteria,

Mycobacterium tuberculosis (M. tuberculosis), as the cause of TB.

TB is a communicable disease that usually affects the lungs. The

airborne route is the predominant mode of transmission, a situation

created when individuals with infectious TB discharge the bacilli from

the lungs when coughing, sneezing, speaking or singing. Some

individuals who breathe contaminated air become infected with TB. Most

often, the immune system responds to fight the infection. Within a few

weeks, the infected lesions become inactive and there is no residual

change except for possible lymph node calcifications. These individuals

will have a positive skin test result. They will harbor the infection

for life. At some time in the future, the infection can progress and

can become an active disease, with pulmonary infiltration, cavitation,

and fibrosis, possibly causing permanent lung damage and even death.

With some exceptions, however, TB is treatable with antimicrobial

drugs. If the active TB is treated early, there will be minimal

residual lung damage. For this reason, individuals who have a TB

exposure incident and develop a TB infection are treated to prevent

progression to active TB disease.

With the introduction of antimicrobial drug treatment in the 1940s

and the creation of programs in the United States such as the U.S.

Public Health Service's Tuberculosis Program, there began a decline in

the incidence of active TB cases in the U.S. From 1953, when active

cases began to be reported in the U.S., until 1984, the number of

annual reported cases declined 74%, from 84,304 (53 per 100,000) to

22,255 (9.4 per 100,000) (Ex. 7-50). However, this steady decline in TB

cases did not continue. Instead, from 1985 through 1992, the number of

reported TB cases increased 20.1% from 22,201 to 26,673 (10.5 cases per

100,000) (Ex. 6-13).

This resurgence in TB brought to attention a number of problems in

the existing TB control programs. The direction of resources to areas

with the highest increase in active cases has caused this increase to

decline. The number of cases reported for 1995 indicates that the rate

of active TB has returned to its 1985 levels. In 1995, a total of

22,813 cases of TB (8.7 per 100,000) was reported to CDC (Ex. 6-34).

While this represents a decline in active TB, the 1995 rate is still

two and one half times greater than the target case rate of 3.5 per

100,000 for the year 2000 and approximately 87 times the goal of less

than one case per million population by the year 2010 proposed by the

Advisory Committee on the Elimination of Tuberculosis (Ex. 6-19).

TB continues to be a national problem. Each year, cases of active

disease are reported in every state in the Nation and in a substantial

majority of counties nationwide. CDC estimated in 1990 that

approximately 10 million people were infected with the tuberculosis

bacterium and that approximately 90% of the new cases of active disease

that arise in the United States come from this already infected group

(Ex. 7-52). Given the recent resurgence of TB, it is likely that a new

population of individuals has been infected as well. Of great concern

are strains of M. tuberculosis that have emerged that are resistant to

several of the first-line anti-TB drugs normally used to treat TB

infection and disease (e.g., isoniazid and rifampin). This drug-

resistant form of the disease, referred to as multidrug-resistant TB or

MDR-TB, is more often a fatal form of TB due to the difficulty in

finding antimicrobial drugs to stop the bacteria's growth and

progressive tissue destruction. In addition, individuals with MDR-TB

often remain infectious for longer periods of time due to delays in

diagnosing resistance patterns and initiating appropriate treatment.

This, in turn, increases the risk that infectious individuals will

transmit the organism to other persons coming in contact with them.

Most of the decreases in reported cases of TB since 1992 have

occurred in areas such as New York City, where resources have been

invested to improve or initiate TB control provisions, such as those

outlined in OSHA's proposed standard. However, the 1995 statistics show

that over the course of four years there is substantial variability in

the increases and decreases of cases reported by each state for any

given year (Ex. 6-34). In 1995, 15 states reported an increase in the

number of TB cases compared with 1994. In addition, a recent study has

shown that MDR-TB has spread to patients in Florida and Nevada, and to

health care workers in Atlanta, Georgia and Miami, Florida. Moreover,

one individual with MDR-TB infected or caused disease in at least 12

people in a nursing home in Denver, Colorado (Ex. 7-259). This study

shows very clearly the ability of TB to be spread to different areas of

the country. This is to be expected given the mobile nature of today's

society and the frequency with which people travel. Immigration also

contributes to the incidence of the disease. For example, while the

number of active TB cases has decreased among U.S. born persons, the

number of foreign born persons reported with TB has increased 63% since

1986, with a 5.4% increase in 1995 (i.e., from 7,627 cases in 1994 to

8,042 cases in 1995). Thirty to fifty percent of these cases were

diagnosed 1 to 5 years after the individual enters the U.S. (Ex. 6-34).

Thus, tuberculosis continues to be a public health problem throughout

the United States.

The following discussion will briefly describe the basic concepts

and terminology associated with TB as well as common factors that

facilitate its transmission from one individual to another. This

discussion will also include a review of studies relating to the

occupational transmission of TB.

Background

TB is a contagious disease caused by the bacterium M. tuberculosis.

Infection is generally acquired by the inhalation of airborne particles

carrying the bacterium. These airborne particles, called droplet

nuclei, can be generated when persons with pulmonary or laryngeal

tuberculosis in the infectious state of the disease cough, sneeze,

speak or sing.

In some individuals exposed to droplet nuclei, tuberculosis bacilli

enter the lung and establish an infection (Ex. 7-52). Once in the

alveoli, the tuberculosis bacilli are taken up by alveolar macrophages

and spread throughout the body by the lymphatic system, until the

immune response limits further growth (usually a period of two to ten

weeks). In most cases the tuberculosis bacilli are contained by the

[[Page 54174]]

immune response. Macrophage cells engulf the bacteria, which limits the

spread of the bacilli. Initial lesions from infection heal; however,

small calcifications called tubercles are formed and may remain a

potential site of later reactivation.

Individuals in this state are infected with TB. They will show a

positive skin test and they are at risk of developing active TB, a risk

they carry throughout their lifetime. In many cases, as described

below, preventive therapy is initiated with anti-TB drugs to prevent

the progression to active TB disease. These drugs are toxic and may

cause adverse effects such as hepatitis. Severe preventive therapy-

associated hepatitis cases have necessitated liver transplants and in

some cases have resulted in death (Ex. 6-10).

When the bacilli are not contained by the immune system, they

continue to grow and invade the tissue, leading to the progressive

destruction of the organ involved, which in most cases is the lung,

i.e., pulmonary tuberculosis. The inflammatory response caused by the

disease produces weakness, fever, chest pain, cough, and, when blood

vessels are eroded, bloody sputum. Also, many individuals have

drenching night sweats over the upper half of the body several times a

week (Ex. 5-80). The extent of disease varies from minimal symptoms of

disease to massive involvement with extensive cavitation and

debilitating constitutional and respiratory symptoms. Since

tuberculosis bacilli are spread throughout the body after the initial

infection, other organs may also be infected and disease may occur at

sites outside the lung, i.e., extrapulmonary tuberculosis.

There are two general stages of TB, tuberculosis infection and

active tuberculosis disease. Individuals with tuberculosis infection

and no active disease are not infectious. These tuberculosis infections

are asymptomatic or subclinical and are only detected by a positive

response to a tuberculin skin test. However, there are some individuals

whose immune system is impaired and cannot mount a sufficient response

to skin test antigens, i.e., they are anergic. Such individuals may be

infected, although they do not show a positive response to the skin

test. Individuals with tuberculosis infection and no disease would have

negative bacteriologic studies and no clinical or radiographic evidence

of tuberculosis disease. However, these individuals are infected for

life and are at risk of developing active TB in the future.

Anti-tuberculosis drugs may be used for individuals with TB

infection but who do not have active disease. In these cases, the

antimicrobials are used as preventive therapy to prevent the onset of

active disease. Because of the toxicity associated with the

antimicrobials, preventive therapy may not be appropriate for all

infected individuals. Various factors are considered to determine

whether an infected individual is an appropriate candidate for

preventive therapy (e.g., age, immune status, how recently the

infection occurred, and other high-risk factors associated with TB)

(Ex. 7-52, pg. 17). Isoniazid is currently the only drug that has been

well tested in humans for its efficacy as preventive therapy (Ex. 7-50,

pg. 61). However, serious side effects may result from isoniazid. A

study in New York for the years 1991 to 1993 examined cases of

hepatitis induced by isoniazid preventive therapy. In this study, 10

patients undergoing preventive therapy for TB were identified at a

transplant center. Eight of these patients had developed hepatitis from

isoniazid. Five received a liver transplant; the other three died while

awaiting a liver donor. In addition, one of the transplant patients

died after transplantation. Thus, preventive therapy may carry

considerable risks for infected individuals.

In those cases where isoniazid cannot be tolerated by the patient

or where it is suspected that infection resulted from exposure to

isoniazid-resistant strains of M. tuberculosis, rifampin may be

recommended for preventive therapy. Considerations for such alternative

drug therapies are made on a case-by-case basis by the health care

provider based on the medical and case history of the infected patient.

Rifampin has adverse side effects as well. However, preventive therapy

using rifampin has not been followed as well as that involving

isoniazid and therefore, its side effects are less well characterized.

Individuals with active TB have clinical and/or radiographic

evidence of disease. The initial laboratory method for diagnosing TB is

the Acid Fast Bacilli (AFB) smear. This is a quick and easy technique

in which body fluids, typically sputum samples, from individuals with

suspected TB are examined for mycobacteria. However, this type of test

only permits a presumptive diagnosis of TB since the test cannot

distinguish between tuberculosis mycobacteria and other non-

tuberculosis mycobacteria. Chest X-rays may also be used to diagnose

active TB; however, some individuals with TB may have X-ray findings

that are atypical of those usually associated with TB (e.g., HIV

infected individuals). The diagnosis of clinically active TB is most

definitively established by the isolation of M. tuberculosis in

culture. However, it may take three to six weeks or longer from

obtaining a culture to getting a result.

Individuals with active TB disease may be infectious, especially if

they are untreated or inadequately treated and if the disease is in the

lungs. The clinical symptoms of pulmonary TB include loss of appetite,

weight loss, fatigue, fever, night sweats, malaise, cough with

productive sputum and/or blood, and chest pain. The extent of the

disease varies from very minimal symptoms to extensive debilitating

constitutional and respiratory symptoms. If untreated, the pulmonary TB

follows a chronic and progressive course in which the tissue is

progressively destroyed. It has been estimated that approximately 40 to

60% of untreated cases result in death (Exs. 5-80, 7-50, and 7-66).

However, even among cured cases of TB, long-term damage can result,

including impaired breathing due to lung damage (Ex. 7-50, pg. 31).

Approximately 90% of immunocompetent adults who are infected do not

develop active TB disease. However, for 10% of infected immunocompetent

adults, either directly after infection or after a latency period of

months, years or even decades, the initial infection progresses to

clinical illness, that is, active TB (Ex. 4B). The risk of developing

active TB is increased for individuals whose immune system is impaired

(i.e., immunocompromised). Such individuals include persons undergoing

treatment with corticosteroid or immunosuppressive drugs (e.g., persons

with organ transplants or persons undergoing chemotherapy for cancer),

persons suffering from malnutrition or chronic conditions such as

asthma and emphysema, and persons infected with the human

immunodeficiency virus (HIV).

The main first-line drugs currently used to treat active TB are

isoniazid, rifampin, pyrazinamide, ethambutol and streptomycin.

Combinations of these antimicrobials are used to attack the

tuberculosis bacilli in the body. Recommended treatment regimens

include two or more drugs to which the bacilli are susceptible, because

the use of a single drug can lead to the development of bacilli

resistant to that drug (Ex. 5-85). Treatment with these first-line

drugs involves a two-phase process: an initial bactericidal phase for

the quick elimination of the bulk of bacilli from most body sites and a

longer-term sterilizing phase for eliminating the remaining bacilli.

[[Page 54175]]

Different regimes of drug treatment (i.e., the types of drugs and

frequency of administration) are recommended depending on the medical

history of the patient involved and the results of drug susceptibility

testing. The U.S. Public Health Service has recommended options for the

initial therapy and dosage schedules for the treatment of drug-

susceptible TB (Ex. 4B). While these antimicrobials are effective in

the treatment of active TB, some of these drugs also have toxic

potential. Adverse side effects of these drugs include hepatitis,

peripheral neuropathy, optic neuritis, ototoxicity and renal toxicity

(Ex. 7-93). Thus, patients undergoing TB therapy must also be monitored

for drug toxicity that may occur from anti-tuberculosis drugs.

Individuals with active disease who are infectious may need to be

hospitalized in order to provide isolation so that they will not infect

other individuals. After the initiation of treatment for active TB,

improvement of the disease can be measured through clinical

observations such as loss of fever, reduction in coughing, increased

appetite and weight gain. A reduction in the number of bacilli in

sputum smears also indicates improvement. Three consecutive negative

sputum smears generally indicate that the individual is no longer

infectious. However, decisions about infectiousness are usually

determined on a case-by-case basis after taking a number of factors

into consideration, such as the presence of cough, the positivity of

sputum smears, and the status or response to chemotherapy. Although no

longer infectious to other individuals, the individual undergoing

treatment still has tuberculosis disease and must continue treatment.

Discontinuing or erratically adhering to the treatment regime can allow

some of the bacilli to survive such that the individual will be at risk

of becoming ill and infectious again (Ex. 7-52, p. 25).

Not all strains of the tuberculosis bacilli are susceptible to all

of the antimicrobials used to treat TB. In some instances, drug-

resistant forms of M. tuberculosis may emerge. Drug resistance may

emerge by 1 of 3 mechanisms (Exs. 5-85; 7-50, pp. 44-47). Drug-

resistant TB may occur naturally from random mutation processes, i.e.,

primary resistance. In addition, drug-resistant TB may result due to

inadequate or erratic treatment, i.e., acquired resistance. In these

cases, erratic or inadequate treatment allows the tuberculosis bacilli

to become resistant to one or several of the drugs being used. Finally,

drug-resistant TB may result due to the active transmission of drug-

resistant TB from an individual already infected with drug-resistant

strains of the tuberculosis bacteria, i.e., transmitted resistance. In

recent years, drug-resistant forms of TB have emerged that are

resistant to two or more of the first-line drugs used to treat TB, such

as isoniazid and rifampin, two of the most effective anti-TB drugs.

These drug-resistant forms of the disease are referred to as multidrug-

resistant TB or MDR-TB. MDR-TB represents a significant form of drug-

resistant TB from a public health standpoint, since its resistance to

the first-line drugs used for therapy complicates finding adequate

therapy regimens that will control the bacilli's growth.

Treatment of drug-resistant TB is determined on a case-by-case

basis, using information from the patient's medical history and drug

susceptibility testing. The recommended course of treatment will vary

depending on the drugs to which the bacilli are susceptible. Compared

to conventional TB drug therapy, MDR-TB, in general, requires more

complex interventions, longer hospitalization and more extensive

laboratory monitoring. The risk of death from such infections is

markedly increased. For example, from January 1990 through September

1992, the CDC investigated eight outbreaks of MDR-TB. In these

outbreaks, 253 patients were infected, of whom approximately 75% died

(Ex. 3-38-A). Many of these were immunocompromised due to infection

with HIV. The interval from the time of TB diagnosis to the time of

death ranged from 4 to 16 weeks, with a median time of 8 weeks.

Factors Affecting Transmission

A number of factors can influence the likelihood of acquiring a

tuberculosis infection: (1) The probability of coming into contact with

an individual with infectious TB, (2) the closeness of the contact, (3)

the duration of the contact, (4) the number of tuberculosis bacilli in

the air, and (5) the susceptibility of the uninfected individual.

Several environmental conditions can influence the likelihood of

infection. For example, the volume of shared air space, the amount of

ventilation, the presence or absence of sunlight, the humidity and the

crowded nature of the living quarters. These types of factors will

affect the probability of acquiring a tuberculosis infection after

being exposed to an individual with infectious TB. MDR-TB is not more

contagious than drug-susceptible forms of the disease. However, due to

time delays in diagnosing resistance patterns and initiating adequate

treatment, individuals with active MDR-TB may remain infectious for

longer periods of time. Consequently, the likelihood that they will

infect other noninfected individuals is increased.

Once infection occurs, other factors may influence the probability

of progressing to the active form of disease. As previously discussed,

10% of immunocompetent adults infected with TB develop active TB. Three

to five percent of untreated immunocompetent adults develop active TB

within the first year after infection (Ex. 7-50, pg. 30; 7-52). Thus,

recently infected individuals have the highest risk of developing

active TB. This risk is increased for individuals whose immune system

is impaired (e.g., persons being treated with immunosuppressive or

glucocorticoid drugs, persons with chronic conditions such as asthma or

emphysema or persons infected with the HIV). The probability of

developing active disease can also be influenced by other conditions

that may alter immune function such as overall decreased general health

status, malnutrition, and increasing age.

The resurgence of TB in the United States from 1985 to 1992 has

been attributed to a number of interacting factors: (1) The inadequate

control of disease in high prevalence areas; (2) the increase in

poverty, substance abuse, poor health status and crowded substandard

living conditions; and (3) the growing number of inmates, residents of

homeless shelters, elderly persons in long-term care facilities,

persons with HIV infection and immigrants from countries with a high

prevalence of TB infection (Ex. 7-50). This increase has begun to

decline, with the 1995 case levels approaching the 1985 levels.

However, a main reason for this decrease is the implementation of TB

control measures, like those proposed in this standard, in selected

areas of the country such as New York City. OSHA believes that

implementation of such measures is necessary to prevent a resurgent

peak such as that observed from 1985 to 1992 and to realize the goal

set out by the National Advisory Committee for the Elimination of

Tuberculosis. The following discussion describes some of the health

effects data related to occupational exposure to TB and illustrates how

the presence of TB control measures influences TB infection and

disease.

Occupational Exposure

Exposure to TB in the health care setting has long been considered

an occupational hazard. With the steady

[[Page 54176]]

decline in reported TB cases from 1953 to 1985, some of the concern for

occupational exposure and transmission also declined. However, from

1985 to 1992 the number of reported cases of TB increased. In addition,

in recent years, several outbreaks of TB among both patients and staff

in hospital settings have been reported to the CDC. These outbreaks

have been attributed to several factors: (1) Delayed recognition of

active TB cases, (2) delayed drug susceptibility testing, (3)

inadequate isolation of individuals with active TB (e.g., lack of

negative pressure ventilation in isolation rooms, recirculation of

unfiltered air, and allowing infectious patients to freely move in and

out of isolation rooms), and (4) performance of high-risk procedures on

infectious individuals under uncontrolled conditions (Ex. 7-50). In

addition to hospitals, outbreaks of TB have also been reported among

the patients, clients, residents and staff of correctional facilities,

drug treatment centers, homeless shelters and long-term health care

facilities for the elderly. The factors contributing to the outbreaks

in these other occupational settings are very similar to those factors

contributing to the outbreaks in hospital settings (i.e., delayed

recognition of TB cases and poor/inadequate ventilation for isolation

areas).

The following is a discussion of some of the studies that have

examined occupational transmission of TB. A large proportion of the

available information comes from exposures occurring in hospitals, in

part because this occupational setting has been recognized for many

years as an area of concern with regards to the transmission of TB.

However, in more recent years this concern has spread to other

occupational settings which share factors identified in the hospital

setting as contributing to the transmission of disease. The following

sections will include a discussion of some of the historical data from

the hospital setting, as well as the more recent data that have been

developed in hospitals and other occupational settings where the

transmission of TB has occurred as a result of the recent resurgences

in the number of active TB cases.

Hospitals--Prior to 1985

Even prior to the recent resurgence of TB in the general

population, studies have shown an increased risk of transmission of TB

to health care workers exposed to individuals with infectious TB. These

studies clearly demonstrate that in the absence of appropriate TB

control measures (e.g., lack of early identification procedures, lack

of appropriate engineering controls), employees exposed to individuals

with infectious TB have become infected and in some cases have

developed active disease.

In 1979, Barrett-Connor (Ex. 5-11) examined the incidence of TB

among currently practicing physicians who graduated from California

medical schools from approximately 1950 to 1979. Through mailed

questionnaires, physicians were asked to provide information that

included their year of graduation from medical school, BCG vaccination

history, history of active TB, results of their tuberculin skin

testing, and the number of patients they were exposed to with active TB

within the past year. They were also asked to classify themselves as

tuberculin positive or negative and to indicate the year of the last

negative and first positive tuberculin test.

Of the 6425 questionnaires mailed out, 4140 responses were received

from currently practicing physicians. Twelve percent of the physicians

had received the BCG vaccine. Sixty-one percent of the unimmunized

physicians, who also had no history of active tuberculosis, considered

themselves to be tuberculin negative. A total of 1542 (42%) reported

themselves as having a positive response to the tuberculin skin test,

with approximately 44 percent of those tuberculosis infections

occurring before entering medical school. Of those infections occurring

before entering medical school, approximately eight percent were

reported as having been a result of contact following work experience

in the hospital prior to entering medical school. For those physicians

infected either during or after medical school, the sources of

infection were reported as occurring as a result of a known patient

contact (45.1%), an unknown contact (41.5%) and a non-patient contact

(13.4%). In some cases, the nonpatient contact was reported as another

physician or another hospital employee. Approximately one in ten of the

physicians infected after entry into medical school developed active TB

disease.

The authors also examined the incidence of infection, measured as

the conversion rates in those remaining negative at the end of

different time intervals (e.g., the last three years of medical school

and five to 10 years after graduation). This examination indicated that

from 1950 to 1975, there was a 78% decrease in tuberculin conversion

rates despite the expanding pool of susceptible medical students (i.e.,

an increasing number of medical students who were tuberculin negative).

Yet despite this overall decrease in infection rates over a 25 year

period, tuberculin conversion rates among recent graduates exceeded 1%

per year and age-specific infection rates among all the physicians

studied were more than twice that of the U.S. population at comparable

ages. The authors did not obtain information from the physicians on

what type of infection control measures were being used in the

facilities where they acquired their infections.

A similar analysis by Geisleler et al. (Ex. 7-46) evaluated the

occurrence of active tuberculosis among physicians graduating from the

University of Illinois medical school between the years 1938 and 1981.

This study, also conducted by questionnaire, reported that among 4575

physicians questioned, there were 66 cases of active TB, of which 23%

occurred after 1970. Sixty-six percent of the cases occurred within 6

years of graduation. In addition, the authors reported that in most

years the incidence of TB was greater among these physicians than the

general population.

Weiss (Ex. 7-45) examined tuberculosis among student health nurses

in a Philadelphia hospital. From 1935 to 1939, before the introduction

of anti-TB drugs and the beginning of the general decline of TB in the

United States, 100% conversion rates were observed among those students

who were initially tuberculin negative. For example, of 643 students

admitted, 43% were tuberculin negative. At the end of only 4 months,

48% were tuberculin positive. At the end of 1 year, 85.9% were

tuberculin positive and by the end of the third year 100% were

positive. Of those students who converted during their student nursing

tenure, approximately 5 percent developed active TB disease.

A decline in the rate of infection was observed over the next 36

years among student nurses at this hospital. The rates of infection

were followed for ten classes of student nurses from 1962 to 1971. The

students had little contact with patients during their first year but

spent 4 weeks of their second year of training on the tuberculosis

wards. Among those students initially tuberculin negative, the average

conversion rate was 4.2% over the nine year period, ranging from 0 to

10.2%. Of the students who converted, 0.6% developed active TB disease.

The authors attributed the decreases in conversion rates to not only

the general decrease in TB disease in the community, but also to the

increased efficiency of surveillance of patients entering the hospital

for the early identification of potential cases of TB and the increased

efficiency of isolation

[[Page 54177]]

for TB patients. Despite the dramatic decreases in conversion rates

among these student nurses, conversion rates were observed at levels as

high as 10% for a given year, indicating that while the infection rates

had decreased substantially since 1939, there still remained a

significant amount of occupational transmission of TB in 1971.

Moreover, this study shows that short term exposure, i.e., 4 weeks, is

capable of infecting hospital employees.

Similar rates of conversion among hospital employees initially

tuberculin negative were observed in a 1977 study by Ruben et al. (Ex.

7-43) which analyzed the results of a tuberculin skin testing program

31 months after its inception at a university hospital in Pittsburgh.

Of 626 employees who were tested twice with the tuberculin skin test,

28 (4.5%) converted from negative to positive. The employees were

classified as either having a ``presumed high degree of patient

exposure'' or a ``presumed low degree of patient exposure''. Employees

presumed to have high patient exposure included nurses, X-ray and

isotope laboratory personnel and central escort workers. Employees

presumed to have low exposure included secretaries, persons in

housekeeping and dietary work, and business office, laundry and central

supply personnel. The rates of conversion for employees with presumed

high exposure (6%) and for employees with presumed low exposure (8%)

were not significantly different. However, this study excluded

physicians and medical and nursing students. These groups of employees

would also presumably have had high exposure to patients since they are

often the hospital staff most directly involved in administering

patient care. Had these employees been included the number of

conversions among employees with presumably high exposure may have been

significantly increased.

The study was not designed to determine the source of exposure for

any of the employees who converted. However, the authors suggested that

the high level of conversions among those employees with presumed low

exposure to patients may have resulted from exposures at home. A

majority of this group was comprised of housekeeping staff who were of

low socio-economic status. The authors also suggested that unrecognized

cases of tuberculosis may be playing an important role in the

occupational transmission of TB in the hospital.

Unrecognized cases of TB have been shown to play a significant role

in the outbreak of TB in a general hospital. In 1972, Ehrenkranz and

Kicklighter (Ex. 5-15) reported a case study in which 23 employees

converted after exposure to a patient with an undetected case of

tuberculosis bronchopneumonia. In this study, the source case was an

individual who was admitted to the emergency room with pulmonary edema.

Upper lobe changes of the lung were noted in the chest X-ray, and TB

was mentioned as a possible cause. However, no sputum cytology was

conducted. The patient spent 3 hours in the emergency room, 57 hours in

a private room and another 67 hours in intensive care until his death.

Treatment of the patient included intubation with an endotracheal tube

and vigorous nasotracheal suctioning. It was only upon microscopic

examination of tissue samples of the lung and lymph nodes after the

autopsy of the patient that tuberculosis mycobacteria were detected.

Employees who worked in the emergency room, the intensive care unit

and on the floor of the private room (NW 3) and who were also

tuberculin negative before the admission of the patient, were retested

to detect possible conversion. In addition, 21 initially tuberculin

negative employees on an adjacent floor (NW 2) were also retested. Of

the 121 employees tested, 24 were identified as having converted to

positive status (21 working on NW 3, 2 working in the intensive care

unit and 1 working on NW 2). No conversions were observed among those

working in the emergency room.

The employees who were retested were classified as either having

close contact (e.g., providing direct care), little contact (e.g., more

distant contact), unknown contact (e.g., no record or recollection of

contact) or indirect contact (e.g., in the same room a day or two after

the patient's stay). Conversions occurred in 50% (13 of 26) of those

employees with close contact, 18.5% (6 of 33) of those with little

contact, 21.4% (3 of 14) of those with unknown contact and 3.7% (1 of

29) of those with indirect contact.

While the majority of conversions seems to have occurred in those

employees on NW 3 who had close or little contact, there also were

employees with more distant contact who were infected. An analysis of

the ventilation of NW 3 indicated that the central air conditioning

recycled 70% of the air with no high efficiency filter and no record of

balancing the air conditioning system, thus allowing the air from the

patients' rooms to mix with and return to the central corridor air. In

addition, smoke tube tests detected direct air flow from the patients'

rooms to the hall corridor. Perhaps the more important factor was that

the patient was not diagnosed with infectious TB until after his death,

by which time he had already infected 24 employees.

These earlier studies illustrate that despite the decrease in TB

morbidity since the advent of anti-tuberculosis drugs in the 1940's,

occupational transmission of TB continues to be a problem. In addition,

while many improvements have been made in infection control procedures

for TB in hospitals, evidence of occupational transmission of TB

continues to be reported.

Hospitals--1985 to Present

As discussed above, the transmission of TB has been well

established as an occupational hazard in the hospital setting. Many

improvements were made in infection control practices. However, the

resurgence in TB from 1985 to 1992 has brought to attention the fact

that many TB control measures have not been implemented or have been

inadequately applied. These studies demonstrate that TB continues to be

an occupational hazard in the hospital setting. In addition, similar to

the earlier studies, the more recent data show that the lack of early

identification procedures and the lack of appropriate ventilation,

performance of high-hazard procedures under uncontrolled conditions and

the lack of appropriate respiratory protection have resulted in the

infection of employees and in some cases the development of active

disease. The more current outbreaks are even more troubling due to the

emergence of multidrug-resistant forms of TB disease, which in some

cases have resulted in fatality rates approaching 75%.

In a 1985 study, Chan and Tabak (Ex. 7-3) investigated the risk of

TB infection among physicians in training at a Miami hospital. In this

study a survey was conducted among 665 physicians in training who were

in their first four years of postgraduate training. Only 404 responded

to the survey, of which 13 were illegible. Another 72 were excluded

because they had received the BCG vaccination. Of the remaining 319

physicians, 55 were tuberculin positive.

Of the 279 who were tuberculin negative at the beginning of their

post graduate training, 15 were excluded because they had more than

four years of training and 43 were excluded because they had not had

repeat skin tests. Of the 221 remaining available for evaluation, 15

converted to positive tuberculin status, of which two developed active

disease.

The overall conversion rate for these physicians was 6.79%. In

addition, the

[[Page 54178]]

authors observed a positive correlation between the rate of conversion

and the duration of postgraduate training. The conversion rate

increased with the duration of training, beginning with a cumulative

percentage of conversion of 2.06% in the first year, 8.62% in the 2nd

year, 11.11% in the third year and 14.29% in the fourth year, resulting

in a linear conversion rate of 3.96% per year. As noted by the authors,

this linear increase suggests the hospital environment as the source of

the infection. In addition, the prevalence rate of conversions in the

hospital (17.24%) was much higher than would have been expected in the

community for individuals of the same age.

The authors suggested that these high rates of conversion may have

been a result of the fact that the hospital in this study encounters 5

to 10 times more active TB cases than most other urban hospitals. In

addition, the physicians in training also are expected to be the first

in line to perform physical evaluations and evaluate body fluids and

secretions. While the authors did not go into detail about what, if

any, TB infection control precautions were taken by these physicians in

training, they did note that the evaluation of body fluids and

secretions was often done in poorly ventilated and ill-equipped

laboratories.

Increased rates of conversion were observed among employees in a

New Orleans hospital in a 1986 study by Ktsanes et al. (Ex. 7-6).

Similar to Miami, New Orleans also has a high rate of TB in the

community. This study examined the skin test conversions among a cohort

of 550 new employees who were followed for five years after assignment

to the adult inpatient services. Of these 550 employees who were

initially tuberculin negative, 17 converted to positive status over the

five-year study period, resulting in an overall five-year cumulative

conversion probability of 5.2%.

Regression analyses were done to examine potential contributing

factors. Factors examined in the regression model included race, job,

age at employment, and department. Only race (i.e., black vs. white

employees) and job (i.e., nursing vs. other jobs) were found to be

associated with skin test conversion. To further examine the potential

job effect, conversions among blacks in nursing and blacks in other

jobs were compared. Overall, the cumulative probability of converting

was higher among blacks in nursing, suggesting that the acquired

infections resulted from employment at the hospital rather than from

the community at large. The authors thus concluded that there is an

increased risk of occupational transmission of TB in TB-prevalent areas

for those in close patient contact jobs.

In 1989, Haley et al. (Ex. 5-16) conducted a case study of a TB

outbreak among emergency room personnel at a Texas hospital. In this

study, a 70 year old male diagnosed with pulmonary TB and undergoing

treatment was diverted, due to respiratory arrest, to Parkland Memorial

Hospital while in route to another hospital. The man was admitted to

the emergency room for approximately 4 hours until he was stabilized.

Afterwards, the patient was placed in an intensive care unit, where he

remained for 2 months until his death.

Six cases of active TB developed among emergency room employees

after exposure to the TB patient, i.e., the index case. Five of these

were among nurses who recalled contact with the index patient and a

sixth case was an orderly who may have been infected from one of the

employee TB cases. In addition, a physician exposed while administering

treatment in the intensive care unit also developed active disease.

Skin test conversions were evaluated for the 153 employees of the

emergency room. Of 112 previously negative employees, 16 had positive

skin tests, including 5 nurses diagnosed with active TB. Fifteen of the

conversions were a result of exposure to the index case. Skin tests

were also evaluated for physicians in the intensive care unit. Of 21

resident physicians, two of whom had intubated the index patient, five

had newly positive reactions to the tuberculin skin tests. One of the

remaining three residents later developed active disease.

The authors attributed the outbreak to several factors. First, the

index case had a severe case of pulmonary TB in which he produced

copious amounts of sputum. Second, sixty percent of the emergency room

air was recirculated without filtration adequate to remove TB bacilli,

allowing for the recirculation of contaminated air. Finally, employees

in the emergency room were provided surgical masks that were

ineffective for protecting against transmission of airborne TB droplet

nuclei. This study illustrates that the lack of effective measures for

controlling TB transmission can result in the infection and development

of active disease in a relatively high number of employees even after

exposure to only one case of active TB.

Similarly, the lack of effective controls while performing high-

hazard, cough-inducing procedures on individuals with infectious TB has

also been shown to result in an increased risk of TB transmission. A

1990 report by Malasky et al. (Ex. 7-41) investigated the potential for

TB transmission from high-hazard procedures by examining tuberculin

skin test conversion rates among pulmonary physicians in training. In

this study, questionnaires were sent annually, for 3 years, to training

programs located in the top 25 cities for TB in 1983. The purpose of

the study was to compare the conversion rates of pulmonary disease

fellows to the conversion rates of infectious disease fellows. It was

presumed that both groups have contact with patients with TB but that

pulmonary disease fellows are usually more involved with invasive

procedures such as bronchoscopies. Information requested on the

questionnaires included the type of fellowship (i.e., pulmonary or

infectious disease fellow), prior tuberculin skin test status,

tuberculin status by the Mantoux technique at the end of the 3 year

fellowship program, history of BCG vaccination, age, sex and ethnicity.

In addition, the pulmonary disease fellows were asked to give

information on the number of bronchoscopies they performed and their

use of masks during the procedure.

Fourteen programs submitted data that were usable. Only programs

that had both pulmonary and infectious disease fellows in the same

system were used for the study. From this information, it was observed

that 7 of 62 (11%) of the pulmonary fellows at risk converted their

tuberculin skin test from negative to positive during the two year

training period. In contrast, only 1 of 42 (2.4%) of the infectious

disease fellows converted. The expected conversion rate from previous

surveys was 2.3%. In addition, the pulmonary disease fellows were

grouped according to tuberculin skin status. Skin test status was

evaluated for its relationship to the number of bronchoscopies

performed and the pattern of mask usage. No correlations were found

with these factors and tuberculin skin status at the end of the

fellowship. The authors suggested that the lack of correlation between

mask usage during bronchoscopies and skin test conversion implies that

masks worn by physicians may be inadequate. While little information

was presented to evaluate this suggestion, the study does suggest that

high-hazard procedures such as bronchoscopies that induce coughing,

performed under uncontrolled conditions, present a risk for TB

transmission.

Pearson et al. (1992) conducted a case-control study to investigate

the factors associated with the development of MDR-TB among patients at

a New

[[Page 54179]]

York City hospital (Ex. 5-24). As a part of this study, tuberculin skin

test conversion rates were compared among health care workers assigned

to wards where patients with TB were frequently admitted (e.g., HIV

unit, general medical ward, respiratory therapy) or rarely admitted

(operating room, orthopedic ward, outpatient clinic, psychiatry ward).

In addition, infection control procedures and ventilation systems were

evaluated.

Of 79 health care workers who were previously negative, 12 (15%)

had newly positive skin tests. Those health care workers who were

assigned to wards where patients with TB were frequently admitted were

more likely to have skin test conversions (i.e., 11 of 32) than health

care workers assigned to wards where patients with TB were rarely

admitted (i.e., 1 of 47).

Evaluations of the infection control procedures and ventilation

systems revealed that patients who were receiving isolation precautions

for suspected or confirmed TB were allowed to go to common areas if

they wore a surgical mask. However, many of the patients did not keep

their masks on when out of their rooms. In addition, neither the

isolation rooms nor rooms used for cough-inducing procedures were under

negative pressure, thus allowing contaminated air to exhaust to the

adjacent corridors.

Edlin et al. (1992) (Ex. 5-9) investigated an outbreak of MDR-TB in

a New York hospital among patients with acquired immunodeficiency

syndrome (AIDS). This study compared the exposure period of AIDS

patients diagnosed with MDR-TB to the exposure period of AIDS patients

with drug-susceptible TB. The date of diagnosis was defined as the date

the sputum sample was collected from which tuberculosis bacteria were

grown in culture. Patients were assumed to be infectious two weeks

before and two weeks after the date of diagnosis. The period of

exposure was the period in which the patient may have been infected

with TB. Because of the rapid progression from infection to disease,

the exposure period was defined as 6 months preceding the date of

diagnosis, excluding the last two weeks.

The patients with MDR-TB were found to be more likely to have been

hospitalized during their exposure periods. Those who were hospitalized

were more likely to have been on the same ward and on the same day as a

patient with infectious TB and were more likely to have been near a

room housing an infectious patient. Examination of the infectious

patients' rooms revealed that only 1 of 16 rooms had negative pressure.

Based on this evidence, the authors concluded that the observed cases

of MDR-TB were a likely result of infections acquired in the hospital

(i.e., primary TB) rather than as a result of the reactivation of

infections acquired in the past. The authors attributed these

nosocomial infections to the lack of adherence to recommended infection

control procedures.

While the primary focus of this study was to investigate the

transmission of TB among patients, the increased likelihood of

nosocomial infections among patients in the hospital would seem equally

likely to apply to health care workers working in the same environment.

A survey of tuberculin skin test conversions revealed an 18% conversion

rate for health care workers who previously had negative skin tests and

were present during this outbreak of MDR-TB. Although no statistics

were reported, the authors stated that the pattern of skin test

conversions suggested an ongoing risk over time rather than a recent

increase during the outbreak period.

Based on an earlier 1990 report from the CDC (Ex. 5-22), Beck-Sague

et al. 1992 (Ex. 5-21) conducted a case-control study to investigate an

outbreak of MDR-TB among the staff and patients in a HIV ward and

clinic of a Miami hospital. As part of the overall study the authors

compared the skin test conversion rates of health care workers in the

HIV ward and clinic to the skin test conversion rates of health care

workers in the thoracic surgery ward where TB patients were rarely

seen. In addition, the authors also evaluated the relationship between

the presence of patients with infectious MDR-TB and patients with

infectious drug-susceptible TB on the HIV ward and the risk of skin

test conversion among the HIV ward health care workers. Infection

control procedures in the HIV ward and clinic were also examined.

All patients with suspected or confirmed TB were placed in

isolation. However, some patients whose complaints were not primarily

pulmonary and whose chest X-rays were not highly suggestive of TB were

not initially suspected of TB and were not placed in isolation.

Patients who were admitted to isolation rooms were allowed to leave TB

isolation 7 days after the initiation of chemotherapy regardless of

clinical or bacteriologic response. Thus, in some instances, patients

with MDR-TB were allowed to leave isolation while they were still

infectious, before drug resistance was recognized. In addition,

patients in isolation rooms sometimes left the doors open, left their

rooms, and/or removed their masks while outside their rooms. Patients

with TB who were readmitted to the HIV ward and who were receiving

anti-TB drugs were not admitted to isolation. In some cases, these

patients were later found to have infectious MDR-TB.

An environmental assessment of the ventilation revealed that among

23 rooms tested with smoke tubes, 6 had positive pressure and many of

the rooms under negative pressure varied from negative to positive

depending on the fan setting and whether the bathroom door was open.

Aerosolized pentamidine administration rooms were also found to have

positive pressure relative to adjacent treatment areas. In addition,

the sputum induction rooms were found to recirculate air back to the

HIV clinic.

Skin test conversions were evaluated for all health care workers

(i.e., nurses and clerical staff) who tested negative on the tuberculin

skin test before the outbreak period, March 1988 through April 1990.

Health care workers on the HIV ward and in the HIV clinic exhibited a

significantly higher rate of skin test conversion than health care

workers on the thoracic surgery ward (e.g., 13/39 vs. 0/15). Ten of the

conversions occurred among the 28 health care workers in the HIV ward.

Among these health care workers, the authors reported a significant

correlation between the risk of infection in health care workers and

the number of days that patients with infectious MDR-TB were

hospitalized on the HIV ward. No correlation was observed between the

risk of infection among health care workers on the HIV ward and the

number of days that patients with infectious drug-susceptible TB were

hospitalized on the ward.

Based on skin test conversions and the evaluation of infection

control practices in the HIV ward and clinic, the authors concluded

that the health care workers most likely were infected by patients on

the HIV ward with MDR-TB. The factors most likely contributing to this

increased risk of infection included: (1) The prolonged infectiousness

and greater number of days that patients with infectious MDR-TB were

hospitalized, (2) the delayed recognition of TB and failure to suspect

infectious TB in patients receiving what proved to be ineffective anti-

TB treatment, (3) the inadequate duration of, and lapses in, isolation

precautions on the HIV ward, and (4) the lack of negative pressure

ventilation in isolation and treatment rooms. While the evidence in

this study primarily points to the transmission of MDR-TB

[[Page 54180]]

from patients to health care workers, many of the problems identified

with infection control procedures and ventilation would also increase

the risk of acquiring drug-susceptible TB.

In addition to MDR-TB outbreak investigations in Miami, in 1993 the

CDC reported an outbreak in New York City in which health care workers

became infected after being exposed to patients with MDR-TB (Ex. 6-18).

In this investigation, for the period December 1990 through March 1992,

32 patients were identified with MDR-TB. Twenty-eight of these patients

had documented exposure to an undiagnosed infectious MDR-TB patient

while all of them were in the HIV ward of the hospital.

During November 1991, health care workers who were assigned to the

HIV inpatient unit and who were also previously negative on the

tuberculin skin test, were given an additional skin test. Of 21 health

care workers tested, 12 (57%) had converted to positive status (7

nurses, 4 aides and 1 clerical worker). None of the health care workers

had used respiratory protection.

An investigation of infection control practices revealed that of 32

patients with MDR-TB, 16 were not initially suspected of TB and in

these cases isolation precautions either were not used or were

instituted late during the patients' hospitalization. In addition,

patients who were admitted to isolation frequently left their rooms and

when in their room the doors were frequently left open. Moreover, all

rooms were found to be under positive pressure relative to the hall.

Thus, similar to the findings in Miami, the results of this study

indicate that the inability to properly isolate individuals with MDR-TB

and also the use of inadequate respiratory protection may increase the

risk of infection among health care workers.

Undiagnosed cases may also present a significant source for

occupational transmission of TB. A case study by Cantanzaro (Ex. 5-14)

described an outbreak of TB infection among hospital staff at a San

Diego hospital where the hospital staff were exposed to a single

patient with undiagnosed TB. In this case, a 64 year old man suffering

from generalized seizures was transferred from a local jail to the

emergency room and later admitted to a four bed intermediate care unit.

While in the intermediate care unit he was treated with anticonvulsants

but continued to have seizures accompanied with vomiting. He was

therefore placed in intensive care where he underwent a variety of

procedures including bronchoscopies and endotracheal intubation. During

his stay, he received frequent chest therapy and suctioning. Three

sputum samples were taken from the patient for smears and cultures. All

AFB smears were negative. However, two cultures were positive for

tuberculosis.

Despite the presence of positive cultures the patient was not

diagnosed with active TB. The problem was not recognized until a

physician on staff later developed symptoms of malaise and slight cough

and requested a tuberculin skin test and was found to be positive.

Because the physician had been tuberculin negative 8 months earlier, a

contact investigation was initiated. As a part of this investigation,

all employees who previously had negative tuberculin tests and who also

worked in the intermediate and intensive care units where the patient

had been treated were given repeat skin tests. Of 45 employees who

previously had negative tuberculin skin tests, 14 (31%) converted to

positive status (6 physicians, 3 nurses, 2 respiratory therapists and 1

clerk). Ten of these conversions were among the 13 previously

tuberculin negative staff members who were present at the time

bronchoscopies were conducted (10/13=76.9%). Four of the conversions

were among 32 susceptible staff members who were not present at the

bronchoscopies (4/32=12.5%). The author thus concluded that being

present during the bronchoscopy of the patient was a major risk factor

in acquiring the TB infection. However, the evidence did not show a

significant correlation between skin test conversion and the type of

exposure, i.e., close (administered direct contact) versus casual (in

the room) contact. Thus, people who were present in the room during the

bronchoscopy had an equal risk of infection as those administering

direct patient care, presumably, as the author suggests, because

droplet nuclei can disperse rapidly throughout the air of a room.

Similarly, Kantor et al. (Ex. 5-18) reported an outbreak of TB

infection among hospital staff exposed to a single undiagnosed case of

TB. The index case in this investigation was a 50 year old man who was

admitted for lung cancer and was receiving chemotherapy, steroids and

radiation treatment. After a month of treatment, the patient complained

of a cough and chest pain and was found to have emphysema requiring

additional drug treatment and a chest tube. However, even after the

emphysema resolved, the patient complained of weakness, loss of

appetite and fever. A sputum culture and smear were conducted for

mycobacteria and found to be negative. Lung X-rays were found to be

irregular but were attributed to the lung cancer. Upon his death the

autopsy revealed extensive necrosis in the lung but tuberculosis was

not suspected. Thus, no cultures for mycobacteria were performed and no

infection control procedures were initiated. It was only upon

histological examination of tissue samples one month later that the

presence of TB was confirmed. Five months later one of the staff

performing the autopsy developed active TB. His only history of

exposure was to the index case.

As a result, a contact investigation was initiated for hospital

personnel who had shared air with the patient during his stay,

including the autopsy staff. Of susceptible hospital staff (i.e., those

not previously found to react positive to the tuberculin skin test),

infection developed in 9 of 56 (16%) exposed employees (4 autopsy

staff, 4 nursing staff and 1 radiology staff). Only 3 of 333 unexposed

personnel were found to have converted to positive tuberculin status at

the hospital during the same period of investigation, thus indicating a

17.8 fold increase in the infection rate for the exposed group.

Undiagnosed cases of TB at time of autopsy were also indicated as

the likely cause for development of active TB among staff and students

in an autopsy room in a Swedish hospital (Ex. 5-19). In this study,

three medical students and one autopsy technician, who were present

during the autopsy of a patient with previously undiagnosed pulmonary

TB, developed active TB. Both the medical students and the autopsy

technician had previously received the BCG vaccine but none had any

other known contact with a tuberculosis subject. Thus, it was concluded

that the tuberculosis infections were most likely to have been

transmitted during the autopsy. The findings of this study further

illustrate the risks that undiagnosed cases of active TB present to

health care workers. The lack of recognition of an active case of TB

often results in a failure to initiate appropriate infection control

procedures and provide appropriate personal protective equipment. In

addition, this study illustrates that, while TB is most often

transmitted by individuals with infectious pulmonary TB who generate

droplet nuclei when they cough or speak, the autopsy procedures on

deceased individuals with pulmonary TB may also aerosolize bacteria in

the lungs and generate droplet nuclei.

Exposure during autopsy procedures was also suspected as a possible

route of TB transmission in an upstate New

[[Page 54181]]

York Medical Examiner's Office (Ex. 7-152). This Medical Examiner's

Office conducted autopsies on deceased inmates from upstate New York

prisons. In 1991, the same year that an outbreak of MDR-TB occurred

among inmates from an upstate New York prison, the Medical Examiner's

office conducted autopsies on 8 inmates with TB, six of whom had

infectious MDR-TB at death and who were also HIV positive and had

disseminated TB disease.

Skin tests were administered to employees who had worked for at

least one month during 1991 at the Medical Examiner's Office. Among 15

employees who had originally tested negative on a baseline skin test, 2

were found to have converted. These two employees worked as morgue

assistants and had recent documented exposure to persons with extensive

disseminated MDR-TB. No potential exposure to TB outside the Medical

Examiner's Office could be found.

The autopsy area of the office had a separate ventilation system.

However, air was returned to a common air plenum, allowing the air to

mix between the autopsy area and other areas of the office. In

addition, the autopsy room was found to be at positive pressure

relative to the adjacent hallway. Employees performing or assisting at

autopsies on persons known to be infected with HIV were required to

wear plastic gowns, latex gloves and surgical masks. Particulate

respirators were not required until November of 1991, after the

installation of germicidal UV lamps. However, this was after the last

MDR-TB autopsy. This study suggests that the conversion of these two

morgue assistants occurred as a result of exposure to aerosolized M.

tuberculosis resulting from autopsy procedures, either as a result of

participation in an autopsy in the autopsy area or from exposure to air

contaminated with aerosolized M. tu

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