First reported case of fatal tuberculosis in a wild African elephant with past human–wildlife contact

Abstract

Tuberculosis is emerging/re-emerging in captive elephant populations, where it causes morbidity and deaths, although no case of TB in wild African elephants has been reported. In this paper we report the first case of fatal TB in an African elephant in the wild. The infection with Mycobacterium tuberculosis was confirmed by post-mortem and histological examinations of a female sub-adult elephant aged >12 years that died in Tsavo East National Park, Kenya, while under treatment. This case is unique in that during its lifetime the elephant had contact with both humans and wild elephants. The source of the infection was unclear because the elephant could have acquired the infection in the orphanage or in the wild. However, our results show that wild elephants can maintain human TB in the wild and that the infection can be fatal.

Pulmonary Tuberculosis in Asian Elephants (Elephas maximus)

“…Riboprobes were synthesized by in vitro transcription of linearized pGEM-T (pGEM-T Vector; Promega, Madison, WI) plasmid templates containing the appropriate insert to generate the antisense or corresponding sense probes using T7 or SP6 RNA polymerase. In vitro transcription was performed using the Maxiscript SP6/T7 kit (Ambion, Austin, TX), with plasmid DNA (0.2 mg) and 35 S-UTP (0.06 mCi; Perkin Elmer, Waltham, MA). Transcription proceeded at 37 C for 3 hours prior to addition of DNAse for an additional 20 minutes.…”

“…Although infection has not been documented in wild elephants to date, captive working elephants in native countries frequently mingle with freeranging elephants, providing opportunity for disease transmission. 30,35 Public health vigilance and effective conservation of this endangered species require a better understanding of the pathogenesis of tuberculosis. Tuberculosis in elephants is typically a subclinical and chronic disease, and the cause of elephant susceptibility to M. tuberculosis infection is currently unknown.…”

Molecular characterization of Mycobacterium tuberculosis isolates from elephants of Nepal

“…8 Since captive elephants are in close contact with humans, it is likely that elephants contracted TB from humans at some point in time as TB has not been reported in wild elephants except for one case in an ex-captive African elephant. 9 Exposure to infected elephants has resulted in transmission of TB to humans as evidenced by tuberculin skin test conversions 10,11,12 or active disease. 13 To clarify the transmission route, an epidemiological study including precise typing of isolated bacteria is 3 needed.…”

Zoonotic Aspects of Tuberculosis: Disease of the past or re-emerging zoonosis?

“…For example, vervet monkeys and chacma baboons are becoming increasingly habituated in the vicinity of human settlements in South Africa and were shown to contract M. tuberculosis possibly through their scavenging behaviour . Recently, the infection was diagnosed in a free-ranging African elephant in Kenya, whereby the source of infection remained unkown as it had spent part of its life in an orphanage (Obanda et al 2013).…”