Recommendations for the diagnosis, treatment and management of tuberculosis, Mycobacterium tuberculosis, in elephants in human care

Abstract

African elephants Loxodonta africana and Asian elephants Elephas maximus are both susceptible to infection by Mycobacterium tuberculosis (Mtb). The Asian elephant has lived in close association with humans in Asian range countries for thousands of years and this close partnership is likely responsible for the exposure of the Asian elephant to this human disease. The confirmation by modern veterinary medicine of the existence of Mtb infection in elephants has only occurred recently after a testing programme was initiated in 1996 in elephant‐holding facilities in the United States. At the time of writing, Mtb is recognized as a disease primarily of Asian elephants in zoos. However, recent identification of tuberculosis in several free‐ranging elephants, both Asian and African, indicates that the disease may be emerging in the threatened wild populations of these species, which may further hinder the survival of wild elephants in some free‐ranging populations. Ante‐mortem diagnosis of the disease in elephants is improving but remains challenging. Protecting both human and elephant health via prevention of Mtb exposure must be part of a preventative‐medicine strategy wherever humans and elephants closely interact. Treatment of Mtb‐infected elephants has been accomplished by many facilities with some promising results. However, many challenges remain, including the side effects of drug therapies and poor compliance to medication administration by the elephant. Inconsistent treatment may potentially result in the bacterium developing resistance to the antibiotics. A brief overview of the diagnosis, treatment and management of Mtb in elephants in human care is provided.

Detection of Mycobacterium tuberculosis complex infection in Asian elephants (Elephas maximus) using an interferon gamma release assay in a captive elephant herd

“…The gold standard of TB diagnosis by trunk wash culture in elephants has serious limitations due to the difficulty of collecting samples and its low sensitivity. Elephants need to be trained to provide samples and the collecting procedures are accompanied with health risk to human involved 19 . More importantly, the trunk wash culture method only detects active TB where the bacteria are shed in mucus, and the negative culture results do not guarantee that the animals are free of TB.…”

Zoo elephant research: contributions to conservation of captive and free‐ranging species

“…() used a combination of isoniazid, rifampin, pyrazinamide and ethambutol administered orally to six and rectally to five Asian elephants as a trial treatment regimen for TB. The current treatment regimen recommended for infected elephants includes isoniazid and rifampin, as well as pyrazinamide and ethambutol, but these guidelines stipulate that ‘pharmacokinetic studies in elephants have not evaluated necessary blood concentrations needed for cure, only the amounts of drugs that need to be administered to achieve blood concentrations’ (Backues & Wiedner, : page 23). Additionally, multi‐drug therapy regimens require careful consideration of drug interactions and individual variables related to age and potential damage to renal, hepatic and gastrointestinal organs (Hunter & Isaza, ).…”

Review of the management of the Asian elephant Elephas maximus EEP: current challenges and future solutions

“…To be able to address these societal concerns, zoos and aquariums must look critically at current practices and find solutions to any issues. In elephants, for example, improvements need to be made in (1) how males are cared for, (2) the genetic management of subspecies and (3) the detection and treatment of diseases such as EEHV and TB (see for example: Luz & Howard, ; Backues & Wiedner, ). Keeping males in suboptimal standards because of the lack of space will raise even more concerns about the welfare of elephants in zoos.…”