The tuberculosis (TB) program includes surveillance testing by accredited veterinarians. What is the primary TB surveillance test that accredited veterinarians perform for cattle?

The tuberculosis (TB) program includes surveillance testing by accredited veterinarians. What is the primary TB surveillance test that accredited veterinarians perform for cattle?

• A. The bovine gamma interferon test
• B. Draw blood and submit serum for a laboratory test
• C. Dual Path Platform VetTB Assay (DPP) for antibody
• D. The caudal fold test

Answer: (D)

The test concept being evaluated is the standard field method used to screen cattle for bovine tuberculosis: the tuberculin skin test. Accredited veterinarians perform the caudal fold test, which is an intradermal injection of bovine tuberculin into the caudal tail fold. After about 72 hours, the injection site is measured for induration. A positive reaction indicates prior sensitization to Mycobacterium bovis and triggers further investigation or removal from the herd as part of surveillance efforts. This skin-based test is favored for routine herd screening because it can be done in the field, provides a consistent, interpretable result, and aligns with established TB surveillance programs. Blood-based tests, such as the interferon-gamma assay or antibody-based tests like the DPP VetTB, exist as supplementary or confirmatory tools in certain scenarios, and drawing blood for laboratory tests is part of those alternative approaches, but they are not the primary surveillance test used by accredited veterinarians for cattle.

The test concept being evaluated is the standard field method used to screen cattle for bovine tuberculosis: the tuberculin skin test. Accredited veterinarians perform the caudal fold test, which is an intradermal injection of bovine tuberculin into the caudal tail fold. After about 72 hours, the injection site is measured for induration. A positive reaction indicates prior sensitization to Mycobacterium bovis and triggers further investigation or removal from the herd as part of surveillance efforts. This skin-based test is favored for routine herd screening because it can be done in the field, provides a consistent, interpretable result, and aligns with established TB surveillance programs. Blood-based tests, such as the interferon-gamma assay or antibody-based tests like the DPP VetTB, exist as supplementary or confirmatory tools in certain scenarios, and drawing blood for laboratory tests is part of those alternative approaches, but they are not the primary surveillance test used by accredited veterinarians for cattle.