Climate change linked to vampire bat expansion and rabies virus spillover

Abstract

Bat-borne pathogens are a threat to global health and in recent history have had major impacts on human morbidity and mortality. Examples include diseases such as rabies, Nipah virus encephalitis, and severe acute respiratory syndrome (SARS). Climate change may exacerbate the emergence of bat-borne pathogens by affecting the ecology of bats in tropical ecosystems. Here, we report the impacts of climate change on the distributional ecology of the common vampire bat Desmodus rotundus across the last century. Our retrospective analysis revealed a positive relationship between changes in climate and the northern expansion of the distribution of D. rotundus in North America. Furthermore, we also found a reduction in the standard deviation of temperatures at D. rotundus capture locations during the last century, expressed as more consistent, less-seasonal climate in recent years. These results elucidate an association between D. rotundus range expansion and a continental-level rise in rabies virus spill-over transmission from D. rotundus to cattle in the last 50 years of the 120-year study period. This correlative study, based on field observations, offers empirical evidence supporting previous statistical and mathematical simulation-based studies reporting a likely increase of bat-borne diseases in response to climate change. We conclude that the D. rotundus rabies system exemplifies the consequences of climate change augmentation at the wildlife-livestock-human interface, demonstrating how global change acts upon these complex and interconnected systems to drive increased disease emergence.

Keywords: bats; climate change; emerging infectious disease; rabies; spillover.

Figure 1.

Range shift of Desmodus rotundus due to climate change. (a) Predicted northward trend (based on ecological niche models) of D. rotundus range (slope = 0.04, R² = 0.06, p < 0.001). (b) Estimates of relative percent contributions of the environmental variables on the distribution of D. rotundus. (c) Model ensemble of D. rotundus distributions from 1901 to 2019. (Darker colors indicate higher agreement in models regarding D. rotundus distributions.) (d) Uncertainty map revealing areas with higher uncertainty (darker colors of blue) with regard to the potential areas of D. rotundus expansion.

Figure 2.

Bat-borne rabies outbreak increase in Latin America. (a) Percentage change in rabies outbreaks in cattle for Latin American countries between the 1970s and 2010s. (b) Regression relationship between northern range expansion of Desmodus rotundus and outbreaks of rabies in Latin America (1970–2019). (Slope = 86.61, R² = 0.36, p < 0.001.) (c) Reduction in temperature seasonality in D. rotundus capture locations across time. (Slope = −0.01, R² = 0.07, p < 0.001.) Black points and lines: distribution of temperature standard deviations of all D. rotundus occurrence locations from each corresponding year.