Mor, S. | bioRxiv Science

bioRxiv2018

The wildlife-livestock interface modulates anthrax suitability in India

Anthrax is a potentially life-threatening bacterial disease that can circulate in wild and domestic animals and subsequently spillover to human contacts with devastating consequences for human and animal health, as well as livestock economies and ecosystem conservation. 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 modeled the geographic suitability of anthrax across India and its associated environmental features using a biogeographical application of machine learning. Both biotic and abiotic features contributed to risk across multiple scales of influence and the wildlife-livestock interface, using elephants as a wildlife sentinel species, 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 wildlife-livestock interface plays an important role in the cycling of anthrax in India. Prevention efforts targeted toward this interface, particularly within anthropogenic ecotones, may yield successes in reducing ongoing transmission between animal hosts and subsequent zoonotic transmission to humans.

epidemiology↗

bioRxiv2017

Climatic influence on the anthrax niche in warming northern latitudes

Climate change is impacting ecosystem structure and function, with potentially drastic downstream effects on human and animal health. Emerging zoonotic diseases are expected to be particularly vulnerable to climate and biodiversity disturbance. Anthrax is an archetypal zoonosis that manifests its most significant burden on vulnerable pastoralist communities. The current study sought to investigate the influence of temperature increases on the landscape suitability of anthrax in the temperate, boreal, and arctic North, where observed climate impact has been rapid. This study also explored the influence of climate relative to more traditional factors, such as livestock distribution, ungulate biodiversity, and soil-water balance, in demarcating high risk landscapes. Machine learning was used to model landscape suitability as the ecological niche of anthrax in northern latitudes. The model identified climate, livestock density and wild ungulate species richness as the most influential landscape features in predicting suitability. These findings highlight the significance of warming temperatures for anthrax ecology in northern latitudes, and suggest potential mitigating effects of interventions targeting megafauna biodiversity conservation in grassland ecosystems, and animal health promotion among small to midsize livestock herds.\n\nSignificance StatementWe present evidence that a warming climate may be associated with the current distribution of anthrax risk in the temperate, boreal, and arctic North. Moreover, projected warming over the coming decades was associated with substantive expansion of this risk. In addition, livestock distribution, ungulate biodiversity, and soil-water balance were also influential to anthrax risk. While these results are sobering for the future health of livestock and pastoralist communities in the northern latitudes, the coincident modulating effect of ungulate biodiversity may suggest targeted ecosystem conservation as a possible buffer against a growing anthrax niche.

epidemiology↗