9 C.F.R. § 77.34 Official tuberculosis tests.
Title 9 - Animals and Animal Products
(a) Single cervical tuberculin (SCT) test. (1) The SCT test is the primary test to be used in individual captive cervids and in herds of unknown tuberculous status. Each captive cervid that responds to the SCT test must be classified as a suspect until it is retested with the CCT test and is either found negative for tuberculosis or is classified as a reactor, unless, with the exception of a designated accredited veterinarian, the testing veterinarian determines that the captive cervid should be classified as a reactor based on its response to the SCT test. A designated accredited veterinarian must classify a responding captive cervid as a suspect, unless the DTE determines, based on epidemiological evidence, that the captive cervid should be classified as a reactor. (2) The SCT test is the primary test to be used in affected herds and in herds that have received captive cervids from an affected herd. When used with affected herds or in herds that have received captive cervids from an affected herd, the SCT test may only be administered by a veterinarian employed by the State in which the test is administered or employed by USDA. In affected herds or herds that have received captive cervids from an affected herd, each captive cervid that responds to the SCT test must be classified as a reactor, unless the DTE determines that the captive cervid should be classified as a suspect because of possible exposure to a tuberculous animal. (b) Comparative cervical tuberculin (CCT) test. (1) The CCT test is a supplemental test that may only be used for retesting captive cervids classified as suspects. The CCT test may be used in affected herds only after the herd has tested negative to at least two whole herd SCT tests and only with the prior written consent of the DTE. The CCT test may not be used as a primary test for herds of unknown tuberculous status. (2) A captive cervid tested with the CCT test must be classified as negative if it has a response to the bovine PPD tuberculin that is less than 1 mm. (3) Unless the testing veterinarian determines that the captive cervid should be classified as a reactor because of possible exposure to a tuberculous animal, a captive cervid tested with the CCT test must be classified as a suspect if: (i) It has a response to the bovine PPD tuberculin that is greater than 2 mm and that is equal to the response to the avian PPD tuberculin; or (ii) It has a response to the bovine PPD tuberculin that is equal to or greater than 1mm and equal to or less than 2mm and that is equal to or greater than the response to the avian PPD tuberculin. (4) A captive cervid tested with the CCT test must be classified as a reactor if: (i) It has a response to the bovine PPD tuberculin that is greater than 2 mm and that is at least 0.5 mm greater than the response to the avian PPD tuberculin; or (ii) It has been classified as a suspect on two successive CCT tests. (iii) Any exceptions to reactor classification under the conditions in paragraph (b)(4)(i) and (b)(4)(ii) of this section must be justified by the testing veterinarian in writing and have the concurrence of the DTE. [65 FR 63517, Oct. 23, 2000, as amended at 71 FR 24806, Apr. 27, 2006]
Title 9: Animals and Animal Products
PART 77—TUBERCULOSIS
Subpart C—Captive Cervids
§ 77.34 Official tuberculosis tests.
