Recent loss of closed forests is associated with Ebola virus disease outbreaks

Abstract

Ebola virus disease (EVD) is a contagious, severe and often lethal form of hemorrhagic fever in humans. The association of EVD outbreaks with forest clearance has been suggested previously but many aspects remained uncharacterized. We used remote sensing techniques to investigate the association between deforestation in time and space, with EVD outbreaks in Central and West Africa. Favorability modeling, centered on 27 EVD outbreak sites and 280 comparable control sites, revealed that outbreaks located along the limits of the rainforest biome were significantly associated with forest losses within the previous 2 years. This association was strongest for closed forests (>83%), both intact and disturbed, of a range of tree heights (5–>19 m). Our results suggest that the increased probability of an EVD outbreak occurring in a site is linked to recent deforestation events, and that preventing the loss of forests could reduce the likelihood of future outbreaks.

Earth observation for public health: Biodiversity change and emerging disease surveillance

“…Here, we consider ecosystem disruption in general. However, both [46] and [47] present findings that suggest disruptions are more likely to promote outbreak events when they incur in such a way as to fragment previously intact ecosystems of a certain minimum diameter. These findings are important for the remote sensing community, because adoption and refinement of EBVs can facilitate real-time measurement of tropical forest fragmentation to a more robust degree than previous methodologies.…”

“…For example, recent work [46,47] has highlighted a critical ecological factor in the emergence of Ebola virus disease in Central Africa: the degree of tropical forest intactness and fragmentation. Here, we consider ecosystem disruption in general.…”

“…The proposed systems architecture of this surveillance tool is described in supplementary figure 1, which describes a spatial reduction approach: beginning at the level of the geographic boundaries of pathogen risk, moderate resolution imagery can be used to define areas of ecosystem intactness, similar to [37] and expanded upon in Refs. [46] and [47]. SRS EBVs are used to identify statistically significant changes in this intactness, or fragmentation, in real time.…”

Changing resource landscapes and spillover of henipaviruses

“…) or broad correlations (e.g., associating deforestation with outbreaks; see Refs. and ). In pteropodid bats and other wildlife, land‐use change may act on different facets of host ecology or pathogen dynamics simultaneously and in interacting ways, making it extremely difficult to disentangle the causal pathways that lead to cross‐species transmission …”

Indentifying and modeling the distribution of cryptic reservoirs of Ebola virus using artificial intelligence

“…Forest fragmentation creates habitat islands associated with EBOV. Spillover from wildlife reservoirs of EBOV to humans occurred mainly in hotspots of fragmented forest and reduction of closed forests (60,61). Tree holes can be described as islands in the forest; the diversity of microbial communities utilizing tree holes can vary depending on size, and tree holes in fact serve as island reservoirs for species, protecting them from a hostile environment (62,63).…”