Effect of an inactivated paratuberculosis vaccine on the intradermal testing of goats for tuberculosis

• Published in: The veterinary journal (1997) Vol. 191; no. 3; pp. 360 - 363
• Main Authors: Chartier, Christophe, Mercier, Pascale, Pellet, Marie-Pierre, Vialard, Jaquemine
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2012; Elsevier
• Subjects: Animals; Bacterial Vaccines - immunology; birds; cattle; Diagnostic test; False Positive Reactions; Goat; Goat Diseases - prevention & control; Goats; herds; interferon-gamma; Intradermal Tests - veterinary; Life Sciences; Mycobacterium; Paratuberculosis; Paratuberculosis - prevention & control; surveys; tuberculin; Tuberculin Test - veterinary; Tuberculosis; Vaccination; vaccines; Vaccines, Inactivated; Diagnostic test; Goat; Tuberculosis; Paratuberculosis; Vaccination
• ISSN: 1090-0233; 1532-2971
• DOI: 10.1016/j.tvjl.2011.03.009

The effect of an inactivated paratuberculosis vaccine on the diagnosis of tuberculosis (TB) in goats was investigated in a herd with a history of clinical paratuberculosis but which was free of TB. Cohorts of animals in 2006, 2008 and 2009, were vaccinated once at 1month of age, and 50% of the 2006 cohort served as unvaccinated controls. The goats were aged 8months, 20months and 3.5years old at the time of the survey. All animals were assessed using a single intradermal injection of bovine tuberculin purified protein derivative (PPD) (SID test), or using both bovine and avian PPD (CID test). An interferon (IFN)-γ assay using both bovine and avian PPD was carried out on the 2006 cohort and was interpreted according to three different ‘cut-off’ points. No unvaccinated (control) animals tested positive to any of the assays, confirming that the herd was TB-free. The SID test had a low specificity in vaccinated animals at 8 and 20months of age, whereas the CID test demonstrated 100% specificity in animals ⩾20months-old. The specificity of IFN-γ assay was less than maximal for vaccinated animals 3.5years old as small numbers of false positives were detected, although this depended on the chosen cut-off point. The study findings demonstrate that the use of an inactivated paratuberculosis vaccine in goats <1month-old in a TB-free herd does not result in false positives to a CID test for TB when performed in animals ⩾20months-old.