Fatal Tuberculosis in a Free-Ranging African Elephant and One Health Implications of Human Pathogens in Wildlife.

Michele A Miller,Alina Sikar-Gang,Peter Buss,Sven D C Parsons,Anzaan Dippenaar,Louis Van Schalkwyk,Robin Warren,Emily Mitchell,W Ray Waters,Konstantin P Lyashchenko,Eduard O Roos,Paul Van Helden,Suelee Robbe-Austerman,Guy Hausler

doi:10.3389/fvets.2019.00018

Abstract

Tuberculosis (TB) in humans is a global public health concern and the discovery of animal cases of Mycobacterium tuberculosis (Mtb) infection and disease, especially in multi-host settings, also has significant implications for public health, veterinary disease control, and conservation endeavors. This paper describes a fatal case of Mtb disease in a free-ranging African elephant (Loxodonta africana) in a high human TB burden region. Necropsy revealed extensive granulomatous pneumonia, from which Mtb was isolated and identified as a member of LAM3/F11 lineage; a common lineage found in humans in South Africa. These findings are contextualized within a framework of emerging Mtb disease in wildlife globally and highlights the importance of the One Health paradigm in addressing this anthroponotic threat to wildlife and the zoonotic implications.

Highlights

Tuberculosis (TB) is the leading cause of death from a bacterial infectious disease in humans
Compared to other Mycobacterium tuberculosis (Mtb) isolates previously reported from elephants, the whole genome sequence was unique (BioProject ID is PRJNA430907; BioSample accession is SAMN08380889; http://www.ncbi.nlm. nih.gov/biosample/8380889). It clustered in the LAM3/F11 family commonly found in human TB patients in South Africa [24] (Figure 6; Table S1). This is the first confirmed case of Mtb disease in a free-ranging African elephant and suggests that this anthroponosis may be a greater threat to wildlife populations in Africa than previously recognized
A presumptive diagnosis of TB was made in a free-ranging African elephant with past human contact in Kenya, but culture of affected tissues was not performed and infection and identity of the suspected Mtb complex (MTBC) organism were not confirmed [25]

Summary

Introduction

Tuberculosis (TB) is the leading cause of death from a bacterial infectious disease in humans. The socioeconomic, and public health costs can be staggering; for example, in South Africa, where 244,053 people were reported with TB in 2016, the national TB program budget (US$244 million) was a significant proportion of the national budget [2] These figures neglect the potential impact of human TB on other incidental host species, especially livestock, and wildlife. Discovery of animal cases of Mtb infection and disease, especially in free-range, multi-host settings, could have significant implications for species management, public health and veterinary disease control, and conservation endeavors This case of Mtb disease in a free-ranging African elephant highlights the importance of applying the One Health paradigm to address anthroponoses where important human pathogens, such as Mtb, can be introduced into wildlife populations [4]

Methods

Results

Conclusion