Serodiagnosis of elephant tuberculosis: a useful tool for early identification of infected elephants at the captive-wild interface

Tuberculosis (TB) is an emerging disease in elephants primarily caused by Mycobacterium tuberculosis (M. tb) and in some occassion by M. bovis. We performed culture and three serological tests—the Elephant TB STAT-PAK,® DPP VetTB® Assay, and MAPIA (multi-antigen print immunoassay)—prospectively on samples from eight elephants in Nepal that died of suspected or confirmed tuberculosis (TB) between 2007 and 2013. Among them, all elephants were reactive to DPP VetTB® Assay, five to Elephant TB STAT-PAK,® and two were reactive to MAPIA. Similarly, six elephants were positive on culture on samples collected antemortem or postmortem. We observed antibody responses months to years before culture confirmation of TB which shows that serological tests can be highly useful for the early diagnosis of TB in elephants. Validated point-of-care serological tests are easily performed in the field and hold promise for improved TB surveillance in other non-domestic species.