Comparison of agar gel immunodiffusion and fecal culture for identification of goats with paratuberculosis.

A large goat herd naturally infected with Mycobacterium paratuberculosis has been monitored for new infections for approximately 21/2 years, using both agar gel immunodiffusion and bacterial culture of feces. On the basis of postmortem confirmation of infection status, both methods had equal diagnostic sensitivity and specificity. The agar gel immunodiffusion test offered distinct advantages in ease of performance and rapidity of test results. It was concluded that serious consideration should be given to the immunodiffusion test as a diagnostic tool in control programs for caprine paratuberculosis.