The narrative claiming that rapid and unprecedented deforestation of primary forests leads to increased human-bat contact in West Africa has been recently advanced by a report published by The ERM Foundation (ERM Foundation, 2015). This study, which compared forest fragmentation patterns in six EVD outbreak sites with a sample of randomly selected sites outside these, found that forest fragmentation was higher in the EVD sites. The inference made from these results is that forest fragmentation, in affecting the foraging and roosting habits of bats, may be indirectly responsible for the expansion of the bat-humans interface, and in so doing increase the risk of EVD. The ERM report also makes a passing suggestion that habitat fragmentation could also increase hunting of smaller prey that become more abundant (linked to the loss of large-bodied fauna), and hence intensifies contact with wild animals. Although the ERM study is probably the first institution to empirically examine possible connections between the state of the forest and EVD outbreaks, its results are still not conclusive. This is because of the small number of sites investigated (6 out of a possible 91 outbreaks) as well as the lack of any tests of alternative hypotheses to investigate the individual influence or interaction of different factors that may be linked to the outbreaks. Given the attention that the ERM report is likely to receive on its publication (planned for the week of 10th August 2015), it is urgent to complete more robust investigations to corroborate if indeed there is a link between Ebola virus outbreaks and deforestation and forest fragmentation. If this association is satisfactorily validated, such a finding could allow a clear entry point to further understand the conditions that increase the risk of Ebola outbreaks and propose adequate mitigation strategies. To evaluate, using spatial and temporal analysis, whether known deforestation episodes and patterns of habitat fragmentation significantly explain the occurrence of reported EVD outbreaks in humans and in animals. We will also examine the relationship between deforestation and habitat fragmentation, changes in potential human-animal contact brought about by land conversion, and the known Ebola outbreaks.
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