Present and future distribution of bat hosts of sarbecoviruses: implications for conservation and public health

Abstract

Global changes in response to human encroachment into natural habitats and carbon emissions are driving the biodiversity extinction crisis and increasing disease emergence risk. Host distributions are one critical component to identify areas at risk of spillover, and bats act as reservoirs of diverse viruses. We developed a reproducible ecological niche modelling pipeline for bat hosts of SARS-like viruses (subgenus Sarbecovirus), given that since SARS-CoV-2 emergence several closely-related viruses have been discovered and sarbecovirus-host interactions have gained attention. We assess sampling biases and model bats’ current distributions based on climate and landscape relationships and project future scenarios. The most important predictors of species distribution were temperature seasonality and cave availability. We identified concentrated host hotspots in Myanmar and projected range contractions for most species by 2100. Our projections indicate hotspots will shift east in Southeast Asia in >2 °C hotter locations in a fossil-fueled development future. Hotspot shifts have implications for conservation and public health, as loss of population connectivity can lead to local extinctions, and remaining hotspots may concentrate near human populations.

A strategy to assess spillover risk of bat SARS-related coronaviruses in Southeast Asia

“…Our analysis identifies regions in southern China, northeastern Myanmar, Lao PDR, and northern Vietnam as having the highest diversity of SARSr-CoV bat host species, in concordance with other recent efforts to map the distribution of SARSr-CoV bat host species 42 . These hotspots of SARSr-CoV bat reservoir host diversity may be particularly fruitful sites for viral discovery of novel SARSr-CoVs, assuming that viral diversity scales with host species diversity 43 .…”

The coevolutionary mosaic of bat betacoronavirus emergence risk

“…19,20 However, both the evolutionary and ecological aspects of emergence risk are higher in southeast Asia-a fact that will only become more relevant, as bats track shifting climates and exchange viruses with other species, creating a hotspot of elevated cross-species transmission unique to the region. 28,46 Bats-and the spillover of their viruses-are also sensitive to anthropogenic factors others than climate change, including deforestation and other kinds of habitat loss, increased stress, and greater contact with potential bridge hosts like domesticated species. 26,[47][48][49] This represents a challenge for both conservation strategies and pandemic prevention, 50 but identifying areas at risk, and protecting the health of bats and ecosystems within those zones, can be a win-win intervention for both.…”

“…The relationship between the underlying pathogen pool and emergence risk is mediated by both human-wildlife interfaces (the probability of spillover) and opportunities for onward horizontal transmission (the probability that spillovers become epidemics) 1 . As a proxy for both, we finally overlaid the risk component from the composite map (see above) with the proportion of built land, as a proxy for a mix of habitat disturbance, potential for bat synanthropy or contact with bridge hosts like livestock, 26,27 and human population density and connectivity 1,28,29 (fig. 5).…”

Present and future distribution of bat hosts of sarbecoviruses: implications for conservation and public health

“…Despite being called bootstrap, this method applies a split sampling method. To evaluate model performance, we randomized occurrence data into 75% : 25% train:test samples to calculate the TSS [34] for each model. Models with TSS > 0.5 were considered as performing above that expected by chance [57].…”