Population Density in Forests Spikes Animal-human Ebola Transmissions

A study conducted by SUNY Downstate Medical Center found people moving to forested areas cause increases in African animal to human Ebola transmissions.

“The reservoir species of the Ebola virus is believed to be fruit bats, with a secondary source being non-human primates. As human populations increase and move into forested areas that are home to these animals, the risk of humans contracting EVD appears to increase, judging from our analysis of EVD outbreaks in Central and West Africa,” the study’s co-contributor Michael G. Walsh, PhD, MPH, said in a statement.

Published in PeerJ, the investigators looked at 21 Ebola cases, which occurred in the Democratic Republic of the Congo or South Sudan from 1976 to 2014. From there they mapped the incidents’ locations using Google Maps and Open Street Maps.

Inversely, they found population-sparse areas with limited vegetation had fewer incidences of Ebola infections.

“This study showed that the spatial dependencies of Ebola Virus spillover were associated with the distribution of population density and vegetation cover in the landscape, even after controlling for climate and altitude,“ the authors noted. “While this is an observational study, and thus precludes direct causal inference, the findings do highlight areas that may be at risk for zoonotic EVD transmission based on the spatial configuration of important features of the landscape.”