Changing resource landscapes and spillover of henipaviruses

Abstract

Old World fruit bats (Chiroptera: Pteropodidae) provide critical pollination and seed dispersal services to forest ecosystems across Africa, Asia, and Australia. In each of these regions, pteropodids have been identified as natural reservoir hosts for henipaviruses. The genus Henipavirus includes Hendra virus and Nipah virus, which regularly spill over from bats to domestic animals and humans in Australia and Asia, and a suite of largely uncharacterized African henipaviruses. Rapid change in fruit bat habitat and associated shifts in their ecology and behavior are well documented, with evidence suggesting that altered diet, roosting habitat, and movement behaviors are increasing spillover risk of bat-borne viruses. We review the ways that changing resource landscapes affect the processes that culminate in cross-species transmission of henipaviruses, from reservoir host density and distribution to within-host immunity and recipient host exposure. We evaluate existing evidence and highlight gaps in knowledge that are limiting our understanding of the ecological drivers of henipavirus spillover. When considering spillover in the context of land-use change, we emphasize that it is especially important to disentangle the effects of habitat loss and resource provisioning on these processes, and to jointly consider changes in resource abundance, quality, and composition.

Novel Insights Into Immune Systems of Bats

“…Understanding host immune responses in bats and developing effective tools to detect and measure these responses in a meaningful way at a population level will allow for the study of variations in antiviral responses in wild bat populations. Wild bat populations are vulnerable to multiple environmental stressors, including seasonal fluctuations in food availability, climatic-stressors, and anthropogenic disturbances (140). Each of these environmental stressors can affect multiple barriers to pathogen spillover (23,141).…”

Macroimmunology: The drivers and consequences of spatial patterns in wildlife immune defence

“…lack of reagents, large home ranges). However, the potential insights about parasite spillover to humans and domestic animals may be especially important from an applied standpoint, when considering that bats host many zoonoses and are increasingly affected by urbanization (Kessler et al, 2018).…”

Seroprevalence of three paramyxoviruses; Hendra virus, Tioman virus, Cedar virus and a rhabdovirus, Australian bat lyssavirus, in a range expanding fruit bat, the Grey-headed flying fox (Pteropus poliocephalus)

“…The geographical distribution and migration of Grey-headed flying foxes and other pteropodids is dictated by the distribution and phenology of food plants. These bats regularly move long distances in search of ephemeral floral and fruit resources in native forests [15,16]. Aggregations of flying foxes can increase rapidly during highly productive flowering events [17].…”