The elephant–livestock interface modulates anthrax suitability in India

23 May 2019
A new collaboration between Dr Michael Walsh and co-investigators from the Manipal Academy of Higher Education and the University of Liverpool have identified the importance of the elephant-livestock in forest fringe areas to the risk of anthrax outbreaks in India

Anthrax is a potentially life-threatening bacterial disease that can spread between wild and livestock animals and humans. Transmission typically occurs indirectly via environmental exposure, with devastating consequences for human and animal health, as well as pastoralist economies. 

India has a high annual occurrence of anthrax in some regions, but a country-wide delineation of risk has not yet been undertaken. The current study modelled the geographical suitability of anthrax across India and its associated environmental features using a biogeographic application of machine learning. Both biotic and abiotic features contributed to risk across multiple scales of influence. The elephant–livestock interface was the dominant feature in delineating anthrax suitability. In addition, water–soil balance, soil chemistry and historical forest loss were also influential. These findings suggest that the elephant–livestock interface plays an important role in the cycling of anthrax in India. Livestock prevention efforts targeting this interface, particularly within anthropogenic ecotones, may yield successes in reducing ongoing transmission between animal hosts and subsequent zoonotic transmission to humans.

Dr Michael Walsh is a landscape epidemiologist with the Marie Bashir Institute for Infectious Diseases and Biosecurity at the Westmead Institute for Medical Research. He is interested in the complex ecologies of zoonotic pathogens and their interaction with hosts, vectors, and environments to shape risk.