Bovine tuberculosis

Question 1

TEST PROCEDURES

Answer 1

Single intradermal test: a single injection of bovine
tuberculin,
Intradermal comparative test: one injection of bovine
tuberculin and one injection of avian tuberculin given
simultaneously.
The dose of tuberculin injected shall be:
 not less than 2 000 IU of bovine tuberculin,
 not less than 2 000 IU of avian tuberculin.
The volume of each injection dose shall not exceed
0,2 ml.

Question 2

The interpretation of reactions

Answer 2

shall be based on clinical
observations and the recorded increase(s) in skin-fold thickness
at the sites of injection 72 hours after injection of tuberculin(s).
 Negative reaction: if only limited swelling is observed, with an
increase of not more than 2 mm in the thickness of the fold of
skin without clinical signs such as diffuse or extensive oedema,
exudation, necrosis, pain or inflammation of the lymphatic ducts
in that region or of the lymph nodes.
 Inconclusive reaction: if no clinical signs are observed and if the
increase in skin-fold thickness is more than 2 mm and less than
4 mm.
 Positive reaction: if clinical signs are observed or there is an
increase of 4 mm or more in the thickness of the fold of skin at
the injection site.
 Animals inconclusive to the single intradermal test
shall be subjected to another test after a minimum of
42 days.
 Animals which are not negative to this second test
shall be deemed to be positive to the test.
 Animals positive to the single intradermal test may
be subjected to an intradermal comparative test if
false positive reaction or interference reaction is
suspected.

Question 3

Intradermal comparative test

Answer 3

for the establishment and maintenance of
officially tuberculosis-free herd status:
 positive: a positive bovine reaction which is more than 4 mm greater
than the avian reaction, or the presence of clinical signs;
 inconclusive: a positive or inconclusive bovine reaction which is
from 1 to 4 mm greater than the avian reaction, and the absence of
clinical signs;
 negative: a negative bovine reaction, or a positive or inconclusive
bovine reaction but which is equal to or less than a positive or
inconclusive avian reaction and the absence of clinical signs in both
cases.
Animals inconclusive to the intradermal comparative test shall be
subjected to another test after a minimum of 42 days. Animals, which
are not negative to this second test, shall be deemed to be positive to
the test.

Question 4

Officially free status of a herd:

Answer 4

 No clinical signs
 All animals over 6w: two official intradermal
tuberculin tests
 1
st: 6 month after the removal of infected
animals,
2
nd: 6 month later;
or 60th days after collection form free herds
 Animals introduced: from officially free herds or
tested (within 30dd)
 Meat inspection, lesions: comp. investigation
 Yearly tuberculin testing
 General measures (isolation of the
holding, record of comp. laboratory
examinations, control of movements of
visitors, animals, vehicles, control of
dogs and cats on the holding etc.)

Question 5

Public health measures:tub

Answer 5

 notification to state medical service
 informing the keeper, owner
 personal disinfection
 protective clothes, gloves and footwear
 control of products