Epidemiology and diagnosis of Mycobacterium tuberculosis in captive Asian elephants (Elephas maximus)

The deaths of two Asian elephants (Elephas maximus) in August 1996 led the United States Department of Agriculture to require the testing and treatmen t of elephants for tuberculosis. From August 1996 to September 1999, Mycoba cterium tuberculosis infection was confirmed by culture in 12 of 118 elepha nts in six herds. Eight diagnoses were made antemortem on the basis of isol ation of M. tuberculosis by culture of trunk wash samples', the remainder ( including the initial two) were diagnosed postmortem. We present the case h istories, epidemiologic characteristics, diagnostic test results, and thera peutic plans from these six herds. The intradermal tuberculin test, enzyme- linked immunosorbent assay serology, the blood tuberculosis test, and nucle ic acid amplification and culture are compared as methods to diagnose M. tu berculosis infection in elephants.