Brucellosis Surveillance; MCI Reactor Prevalence Rates

DEPARTMENT OF AGRICULTURE

Animal and Plant Health Inspection Service

9 CFR Part 78

[Docket No. 93-024-1]

Brucellosis Surveillance; MCI Reactor Prevalence Rates

AGENCY: Animal and Plant Health Inspection Service, USDA.

ACTION: Proposed rule.

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SUMMARY: We are proposing to amend the brucellosis regulations to

eliminate the requirement that States maintain specified Market Cattle

Identification (MCI) reactor prevalence rates to maintain their

official classifications. We are proposing instead to require the

States to successfully close (epidemiologically investigate and

resolve) certain percentages of cases detected through the MCI program.

We believe these amendments would better serve Federal and State animal

health officials in their efforts to prevent the interstate spread of

brucellosis.

DATES: Consideration will be given only to comments received on or

before February 14, 1994.

ADDRESSES: Please send an original and three copies of your comments to

Chief, Regulatory Analysis and Development, PPD, APHIS, USDA, room 804,

Federal Building, 6505 Belcrest Road, Hyattsville, MD 20782. Please

state that your comments refer to Docket No. 93-024-1. Comments

received may be inspected at USDA, room 1141, South Building, 14th

Street and Independence Avenue SW., Washington, DC, between 8 a.m. and

4:30 p.m., Monday through Friday, except holidays. Persons wishing to

inspect comments are encouraged to call ahead on (202) 690-2817 to

facilitate entry into the comment reading room.

FOR FURTHER INFORMATION CONTACT: Dr. M.J. Gilsdorf, National

Brucellosis Epidemiologist, Cattle Diseases and Surveillance Staff, VS,

APHIS, USDA, room 731, Federal Building, 6505 Belcrest Road,

Hyattsville, MD 20782, (301) 436-4918.

SUPPLEMENTARY INFORMATION:

Background

Brucellosis is an infectious disease of certain animals and humans.

In its principal animal hosts, it is characterized by abortion and

impaired fertility. Through a cooperative Federal-State effort, the

United States is now approaching total eradication of the field strain

Brucella abortus in domestic cattle and bison herds. As of May 1993,

there were only 337 known infected cattle and bison herds, and the U.S.

Department of Agriculture (USDA) had declared 32 States, Puerto Rico,

and the U.S. Virgin Islands free of the disease. Fewer than 500 new

infected herds were identified last year.

The regulations in 9 CFR part 78 (referred to below as the

regulations) govern the interstate movement of cattle, bison, and swine

to prevent the spread of brucellosis. Section 78.1 defines the terms

used in the regulations. In accordance with Sec. 78.1, States and areas

can be classified as Class Free, Class A, Class B, or Class C. These

terms refer to stages of the eradication process as determined by the

USDA's Animal and Plant Health Inspection Service (APHIS) and State

animal health officials. Class Free States and areas are considered to

be free of Brucella abortus in all domestic livestock, and Class C

States and areas have the highest levels of brucellosis infection.

Section 78.1 sets forth the standards States or areas must meet to

achieve and maintain each of the classifications.

One standard for classification is the Market Cattle Identification

(MCI) reactor prevalence rate. Under the MCI program, slaughtering

establishments must collect blood samples from 95 percent of all cows

and bulls 2 years of age and older (known as MCI test cattle). The

samples are then subjected to an official brucellosis test. Animals

that have serologically positive results to the official brucellosis

test administered under the MCI program are MCI reactors. The

regulations require animal health officials to trace MCI reactors to

the farm of origin and conduct an epidemiologic investigation, to

evaluate the risk that brucellosis could spread from the farm of

origin. Class Free and Class A States and areas must trace at least 90

percent of all MCI reactors to the farm of origin, and Class B and

Class C States and areas must trace at least 80 percent to the farm of

origin. When required by the results of the epidemiologic

investigation, herd blood tests must be conducted or the herds must be

confined to the premises under quarantine. Examples of when herd

testing or quarantine may not be necessary include cases where

epidemiologic investigation reveals the MCI reactor results were not

caused by field strains of Brucella, or that the herd has been or will

be sent to slaughter.

The MCI reactor prevalence rate is the rate of infection in a State

or area's cattle population based on the percentage of MCI reactors

found in the total number of MCI tested cattle. Under the regulations,

Class Free States and areas must maintain a 12-consecutive-month MCI

reactor prevalence rate not to exceed 0.050 percent. For Class A States

and areas, the rate must not exceed 0.10 percent, and for Class B

States and areas, the rate must not exceed 0.30 percent. Class C States

and areas have an MCI reactor prevalence rate that exceeds 0.30

percent. Class Free, Class A, and Class B States and areas that exceed

the required percentages may be reclassified to a lower classification.

Tests used to identify MCI reactors detect not only serum titers

caused by brucellosis infection but also serum titers caused by certain

other organisms and by vaccination. As a result of such spurious

titers, an estimate of brucellosis prevalence based solely on the MCI

reactor prevalence rate in a State or area would overestimate the rate

of brucellosis infection. Nevertheless, the MCI reactor data has been

helpful to Federal and State animal health officials who use the rates

of the individual States and areas to reveal trends and to compare

their progress in eradicating brucellosis.

When the United States had thousands of infected herds, we did not

consider the effect of spurious titers on the States' and areas' MCI

reactor prevalence rates to be significant. However, as the level of

brucellosis infection in this country has declined, the proportion of

spurious titers in the MCI reactor prevalence rates has increased. As a

result, in Class Free States and areas, the MCI reactor prevalence rate

may consist entirely of spurious titers. Therefore, we no longer

believe a State or area's MCI reactor prevalence rate is a good

indication of its eradication progress, and we are proposing to

eliminate the requirement in the regulations that States and areas meet

specific MCI reactor prevalence rates to maintain their official

classifications.

If States no longer need to meet specific MCI reactor prevalence

rates, we believe it is even more important for the States to

concentrate on the activities required following identification of an

MCI reactor (tracebacks, epidemiologic investigations, and, usually,

herd testing or quarantine). The epidemiologic investigation and herd

testing can reveal whether an MCI reaction is a spurious titer or a

valid indication of brucellosis. If herd testing reveals one or more

animals that test positive to the official test for brucellosis

(brucellosis reactors), all other animals in the herd are considered

brucellosis exposed. Brucellosis reactor cattle and brucellosis exposed

cattle may move interstate only in accordance with subpart B of part 78

(Secs. 78.5 through 78.14), to control the spread of brucellosis.

If a herd is quarantined in lieu of testing following epidemiologic

investigation of an MCI reactor herd, the quarantine protects against

the possibility that the herd may be infected and could spread

brucellosis.

Herd testing or quarantine only occur for MCI reactor cases that

are ``successfully closed'' (defined below). The larger the number of

MCI reactor cases that are not successfully closed, the greater the

possibility that brucellosis could spread from herds associated with

the uninvestigated MCI reactors. Therefore, we are proposing to require

that a minimum percentage of MCI reactor cases must be successfully

closed.

We would consider MCI reactor cases that have been traced to the

farm of origin to be successfully closed when: (1) An epidemiologic

investigation is completed within specified time limits; and (2) the

herd is tested, or State or APHIS animal health officials confine the

animals to their premises under quarantine; or (3) State or APHIS

animal health officials determine there is justification for not

testing the herd or quarantining it. We propose to add to Sec. 78.1 a

definition of ``successfully closed case'' that reflects this standard

for successful closure.

For Class Free and Class A States, animal health officials would

have to complete the epidemiologic investigation within 15 days after

they are notified by the cooperative State-Federal laboratory that

brucellosis reactors were found on an MCI test. For Class B and Class C

States, the time limit would be 30 days. This time standard for

completing the epidemiologic investigation is the same standard

required in the current regulations. Experience with brucellosis

program operations has shown the time limits to be long enough to be

workable for animal health officials, and short enough to support

effective controls on the spread of brucellosis.

We believe there are circumstances that would constitute acceptable

justification for not testing or quarantining a herd following an MCI

reactor traceback. The current regulations merely state that herd

testing or quarantine will be employed ``[W]hen required by the results

of the epidemiologic investigation.'' We would like to provide more

specific guidance concerning when it would be justified to forego herd

testing or quarantine.

We are proposing to require that herd blood tests be conducted or

the herd be confined to the premises under quarantine within 30 days

after notification that brucellosis reactors were found on the MCI

test, unless a designated epidemiologist determines that:

1. The brucellosis reactor is located in a herd in a different

State than the State where the MCI blood sample was collected. In such

cases a State representative or APHIS representative must give written

notice of the MCI test results to the State animal health official in

the State where the brucellosis reactor is located; or,

2. Evidence indicates that the brucellosis reactor is from a herd

that no longer presents a risk of spreading brucellosis, or is from a

herd that is unlikely to be infected with brucellosis. Such evidence

could include, but is not limited to, situations where:

a. The brucellosis reactor is traced back to a herd that has been

sold for slaughter in entirety. In this case, the potential for the

herd to spread brucellosis no longer exists.

b. The brucellosis reactor is traced back to a herd that is

certified brucellosis free and is 100-percent vaccinated. In such cases

it is probable that the MCI test was a false positive, due to a titer

caused by the vaccine.

c. The brucellosis reactor showed a low titer on the MCI test and

is traced back to a dairy herd that is 100 percent vaccinated and has

tested negative to the most recent brucellosis ring test required by

the regulations. This is another case where the probability of a false

positive or other error in the MCI test is far greater than the

probability that the herd of origin is affected by brucellosis.

Animal health officials could report a traceback to a farm of

origin in another State as a successfully closed case because we do not

expect animal health officials to conduct epidemiologic investigations

and herd testing in another State. However, as part of successfully

closing the case we would require them to notify in writing the State

animal health official in the State where the farm of origin is located

so officials in that State could take proper follow-up action.

Under this proposal, Class Free and Class A States and areas would

need to successfully close at least 95 percent of the MCI reactor cases

traced to the farm of origin, and Class B and Class C States and areas

would need to successfully close at least 90 percent of such cases.

This means that 1 in 20 MCI reactor cases could be left unclosed in

Class Free and Class A States, and 1 in 10 reactor cases could be left

unclosed in Class B and Class C States.

If adopted, this proposal would reduce current recordkeeping

requirements for the States. While State officials would still need to

compile data, the time involved should be much less than what is

currently required for computing the MCI reactor prevalence rate. Under

our proposal, States would focus their recordkeeping on a fairly small

number of MCI reactors, rather than the much larger number of cattle

with negative MCI test results. States would no longer need to count

all cattle tested, separate out cattle from other States, and then

calculate an MCI reactor prevalence rate based on the number of their

State's cattle that were tested and the number of MCI reactors found

through such testing. Instead, each State would need to include in its

annual report to APHIS the percentage of MCI reactor cases it

successfully closes.

Executive Order 12866 and Regulatory Flexibility Act

We are issuing this proposed rule in conformance with Executive

Order 12866. Based on information compiled by the Department, we have

determined that this proposed rule:

(1) Would have an effect on the economy of less than $100 million;

(2) Would not adversely affect in a material way the economy, a

sector of the economy, productivity, competition, jobs, the

environment, public health or safety, or State, local, or tribal

governments or communities;

(3) Would not create a serious inconsistency or otherwise interfere

with an action taken or planned by another agency;

(4) Would not alter the budgetary impact of entitlements, grants,

user fees, or loan programs or rights and obligations of recipients

thereof; and

(5) Would not raise novel legal or policy issues arising out of

legal mandates, the President's priorities, or principles set forth in

Executive Order 12866.

Only State animal health agencies would be affected by this

proposed rule; it would have no effect on the private sector. State

animal health officials would need to provide information on only the

MCI reactors detected each month instead of total numbers of MCI test

cattle slaughtered. They would also need to maintain records of the

numbers of MCI reactor cases that are successfully closed and report

the percentage of successfully closed cases annually to APHIS. The

States are already required to carry out the activities that constitute

successful case closure.

Under these circumstances, the Administrator of the Animal and

Plant Health Inspection Service has determined that this action would

not have a significant economic impact on a substantial number of small

entities.

Executive Order 12372

This program/activity is listed in the Catalog of Federal Domestic

Assistance under No. 10.025 and is subject to Executive Order 12372,

which requires intergovernmental consultation with State and local

officials. (See 7 CFR part 3015, subpart V.)

Executive Order 12778

This proposed rule has been reviewed under Executive Order 12778,

Civil Justice Reform. If this proposed rule is adopted:

(1) All State and local laws and regulations that are in conflict

with this rule will be preempted;

(2) No retroactive effect will be given to this rule; and

(3) Administrative proceedings will not be required before parties

may file suit in court challenging this rule.

Paperwork Reduction Act

In accordance with the Paperwork Reduction Act of 1980 (44 U.S.C.

3501 et seq.), the information collection or recordkeeping requirements

included in this proposed rule will be submitted for approval to the

Office of Management and Budget. Please send written comments to the

Office of Information and Regulatory Affairs, OMB, Attention: Desk

Officer for APHIS, Washington, DC 20503. Please send a copy of your

comments to:

(1) Chief, Regulatory Analysis and Development, PPD, APHIS, USDA,

room 804, Federal Building, 6505 Belcrest Road, Hyattsville, MD 20782;

and

(2) Clearance Officer, OIRM, USDA, room 404-W, 14th Street and

Independence Avenue SW., Washington, DC 20250.

List of Subjects in 9 CFR Part 78

Animal diseases, Bison, Cattle, Hogs, Quarantine, Reporting and

recordkeeping requirements, Transportation.

Accordingly, 9 CFR part 78, subpart A, would be amended as follows:

PART 78--BRUCELLOSIS

1. The authority citation for part 78 would continue to read as

follows:

Authority: 21 U.S.C. 111-114a-1, 114g, 115, 117, 120, 121, 123-

126, 134b, 134f; 7 CFR 2.17, 2.51, and 371.2(d).

2. Section 78.1 would be amended as follows:

a. A new definition of Successfully closed case would be added, in

alphabetical order, to read as set forth below.

b. In the definition of Class A State or area, paragraph (a)(2)(ii)

would be revised to read as set forth below and paragraph (c) would be

removed.

c. In the definition of Class B State or area, paragraph (a)(2)(ii)

would be revised to read as set forth below and paragraph (c) would be

removed.

d. In the definition of Class C State or area, paragraph (a)(2)(ii)

would be revised to read as set forth below and paragraph (c) would be

removed.

e. In the definition of Class Free State or area, paragraph

(a)(2)(ii) would be revised to read as set forth below and paragraph

(c) would be removed.

Sec. 78.1 Definitions.

* * * * *

Class A State or area. * * *

(a) * * *

(2) * * *

(ii) Brucellosis reactors--(A) Tracebacks. At least 90 percent of

all brucellosis reactors found in the course of MCI testing must be

traced to the farm of origin.

(B) Successfully closed cases. The State or area must successfully

close at least 95 percent of the MCI reactor cases traced to the farm

of origin during the 12-consecutive-month period immediately prior to

the most recent anniversary of the date the State or area was

classified Class A. To successfully close an MCI reactor case, State

representatives or APHIS representatives must conduct an epidemiologic

investigation at the farm of origin within 15 days after notification

by the cooperative State-Federal laboratory that brucellosis reactors

were found on the MCI test. Herd blood tests must be conducted or the

herd must be confined to the premises under quarantine within 30 days

after notification that brucellosis reactors were found on the MCI

test, unless a designated epidemiologist determines that:

(1) The brucellosis reactor is located in a herd in a different

State than the State where the MCI blood sample was collected. In such

cases a State representative or APHIS representative must give written

notice of the MCI test results to the State animal health official in

the State where the brucellosis reactor is located; or,

(2) Evidence indicates that the brucellosis reactor is from a herd

that no longer presents a risk of spreading brucellosis, or is from a

herd that is unlikely to be infected with brucellosis. Such evidence

could include, but is not limited to, situations where:

(i) The brucellosis reactor is traced back to a herd that has been

sold for slaughter in entirety;

(ii) The brucellosis reactor is traced back to a herd that is

certified brucellosis free and is 100-percent vaccinated; or,

(iii) The brucellosis reactor showed a low titer in the MCI test

and is traced back to a dairy herd that is 100 percent vaccinated and

has tested negative to the most recent brucellosis ring test required

by this section for herds producing milk for sale.

* * * * *

Class B State or area. * * *

(a) * * *

(2) * * *

(ii) Brucellosis reactors--(A) Tracebacks. At least 80 percent of

all brucellosis reactors found in the course of MCI testing must be

traced to the farm of origin.

(B) Successfully closed cases. The State or area must successfully

close at least 90 percent of the MCI reactor cases traced to the farm

of origin during the 12-consecutive-month period immediately prior to

the most recent anniversary of the date the State or area was

classified Class B. To successfully close an MCI reactor case, State

representatives or APHIS representatives must conduct an epidemiologic

investigation at the farm of origin within 30 days after notification

by the cooperative State-Federal laboratory that brucellosis reactors

were found on the MCI test. Herd blood tests must be conducted or the

herd must be confined to the premises under quarantine within 30 days

after notification that brucellosis reactors were found on the MCI

test, unless a designated epidemiologist determines that:

(1) The brucellosis reactor is located in a herd in a different

State than the State where the MCI blood sample was collected. In such

cases a State representative or APHIS representative must give written

notice of the MCI test results to the State animal health official in

the State where the brucellosis reactor is located; or,

(2) Evidence indicates that the brucellosis reactor is from a herd

that no longer presents a risk of spreading brucellosis, or is from a

herd that is unlikely to be infected with brucellosis. Such evidence

could include, but is not limited to, situations where:

(i) The brucellosis reactor is traced back to a herd that has been

sold for slaughter in entirety;

(ii) The brucellosis reactor is traced back to a herd that is

certified brucellosis free and is 100-percent vaccinated; or,

(iii) The brucellosis reactor showed a low titer in the MCI test

and is traced back to a dairy herd that is 100 percent vaccinated and

has tested negative to the most recent brucellosis ring test required

by this section for herds producing milk for sale.

* * * * *

Class C State or area. * * *

(a) * * *

(2) * * *

(ii) Brucellosis reactors.--(A) Tracebacks. At least 80 percent of

all brucellosis reactors found in the course of MCI testing must be

traced to the farm of origin.

(B) Successfully closed cases. The State or area must successfully

close at least 90 percent of the MCI reactor cases traced to the farm

of origin during the 12-consecutive-month period immediately prior to

the most recent anniversary of the date the State or area was

classified Class C. To successfully close an MCI reactor case, State

representatives or APHIS representatives must conduct an epidemiologic

investigation at the farm of origin within 30 days after notification

by the cooperative State-Federal laboratory that brucellosis reactors

were found on the MCI test. Herd blood tests must be conducted or the

herd must be confined to the premises under quarantine within 30 days

after notification that brucellosis reactors were found on the MCI

test, unless a designated epidemiologist determines that:

(1) The brucellosis reactor is located in a herd in a different

State than the State where the MCI blood sample was collected. In such

cases a State representative or APHIS representative must give written

notice of the MCI test results to the State animal health official in

the State where the brucellosis reactor is located; or,

(2) Evidence indicates that the brucellosis reactor is from a herd

that no longer presents a risk of spreading brucellosis, or is from a

herd that is unlikely to be infected with brucellosis. Such evidence

could include, but is not limited to, situations where:

(i) The brucellosis reactor is traced back to a herd that has been

sold for slaughter in entirety;

(ii) The brucellosis reactor is traced back to a herd that is

certified brucellosis free and is 100-percent vaccinated; or,

(iii) The brucellosis reactor showed a low titer in the MCI test

and is traced back to a dairy herd that is 100 percent vaccinated and

has tested negative to the most recent brucellosis ring test required

by this section for herds producing milk for sale.

* * * * *

Class Free State or area. * * *

(a) * * *

(2) * * *

(ii) Brucellosis reactors.--(A) Tracebacks. At least 90 percent of

all brucellosis reactors found in the course of MCI testing must be

traced to the farm of origin.

(B) Successfully closed cases. The State or area must successfully

close at least 95 percent of the MCI reactor cases traced to the farm

of origin during the 12-consecutive-month period immediately prior to

the most recent anniversary of the date the State or area was

classified Class Free. To successfully close an MCI reactor case, State

representatives or APHIS representatives must conduct an epidemiologic

investigation at the farm of origin within 15 days after notification

by the cooperative State-Federal laboratory that brucellosis reactors

were found on the MCI test. Herd blood tests must be conducted or the

herd must be confined to the premises under quarantine within 30 days

after notification that brucellosis reactors were found on the MCI

test, unless a designated epidemiologist determines that:

(1) The brucellosis reactor is located in a herd in a different

State than the State where the MCI blood sample was collected. In such

cases a State representative or APHIS representative must give written

notice of the MCI test results to the State animal health official in

the State where the brucellosis reactor is located; or,

(2) Evidence indicates that the brucellosis reactor is from a herd

that no longer presents a risk of spreading brucellosis, or is from a

herd that is unlikely to be infected with brucellosis. Such evidence

could include, but is not limited to, situations where:

(i) The brucellosis reactor is traced back to a herd that has been

sold for slaughter in entirety;

(ii) The brucellosis reactor is traced back to a herd that is

certified brucellosis free and is 100-percent vaccinated; or,

(iii) The brucellosis reactor showed a low titer in the MCI test

and is traced back to a dairy herd that is 100 percent vaccinated and

has tested negative to the most recent brucellosis ring test required

by this section for herds producing milk for sale.

* * * * *

Successfully closed case. Follow up of an MCI reactor traceback

with an epidemiologic investigation which results in brucellosis

testing or quarantine of the herd of origin, or a determination by a

designated brucellosis epidemiologist that justification exists for not

testing or quarantining the herd of origin.

* * * * *

Done in Washington, DC, this 10th day of January 1994.

Patricia Jensen,

Acting Assistant Secretary, Marketing and Inspection Services.

[FR Doc. 94-994 Filed 1-13-94; 8:45 am]

BILLING CODE 3410-34-P