Climate change has increased the risk of spreading bat-borne pathogens

In a recently published study bioRxiv* Preprint servers, the researchers retrospectively assessed the association between climate change and the risks of disease spread induced by changes in bat distribution, based on historical climate data and vampire bat occurrence data for the past century (1900-2020).

Study: Climate change has affected spillover risk from bat-borne pathogens. Credit: Pablo Jacinto Yoder/Shutterstock

background

Bat-borne viruses have threatened global public health with increased human morbidity and mortality. Examples of bat-borne diseases include rabies, Ebola, severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) infection and SARS-CoV-2 infection or coronavirus disease 2019 (COVID-19). Studies on the impact of climate change on disease are scarce, focusing on vector-borne diseases based on future climate change projections rather than empirical retrospective data, which could hamper progress in global preparedness against infectious diseases.

Desmodus rotundus species (common vampire bat) is considered a key species for the transmission of rabies to other animal species (spillover) in the Latin American regions. There is an ongoing debate as to whether Desmodus rotundus (common vampire bat) will shift north in the United States (USA) to warm-temperate areas at higher latitudes due to climate change in the future.

About the study

In the present study, researchers assessed the impact of climate change on transmission risks of bat-borne pathogens based on climate and vampire bat distribution data from the last century.

Desmodus rotundus-Transmitted rabies is a well-documented and understood model of diseases transmitted directly to animals and humans in the tropical and subtropical areas of the Americas, from which rabies is commonly transmitted Desmodus rotundus to cattle. Outbreaks of bat-borne rabies in cattle have increased over the past 40 years, suggesting an increase in spillover events in America. In addition, there is an ongoing debate about the possible northward shift in the range of D. rotundus to more temperate areas in the United States (US).

Therefore, the team evaluated changes in Desmodus rotundus Distribution in response to climate change using ecological niche modeling and machine learning between 1901 and 2019. Data on D rotundus Occurrence over the past century and historical climate data from the CRUTS database (Climatic Research Unit Gridded Time Series) were used for the analysis.

Boxplots of annual bovine rabies outbreaks were constructed and the percent change in bovine rabies outbreaks for Latin America assessed. In addition, uncertainty maps were assessed to identify areas of high uncertainty regarding the potential regions D rotundus range extension.

Results

No statistically significant changes were found in the overall range of Desmodus rotundus abundance and distribution in the above period; However, the geographic reach of D rotundus It has been found to shift northward. The results suggest that the common vampire bat species, with an annual average speed of five miles per year, has been steadily encroaching on northern Mexican regions and may expand its range further into the US continent.

Additionally, there are some regions of uncertainty for Desmodus rotundus Range extensions were found by the team that included the Andean highlands and temperate regions of the US. The study variable affecting the Desmodus rotundus Area shift most was temperature variation, indicating that the frequency and distribution of D rotundus and associated potential disease transmissions have been linked to climatic variability.

Conclusions

Overall, the results of the study indicated that climate change, particularly temperature fluctuations, could affect the distribution of bats and the associated risk of bat-borne disease spread. The authors believe the present study is the first of its kind to assess the impact of climate change on the distribution patterns and transmission risks of bat-borne pathogens.

They therefore recommend further research into the link between climate change and bat-borne diseases, and incorporating the impact of climate variability on bat distribution into safety measures. The results showed that climatic variations had a direct impact on the risk of rabies occurrence by increasing virus reservoirs in temperate regions of America, thereby increasing the risks of infection in humans, livestock and wildlife.

The study has provided evidence of an expansion in the range of bats driven by climatic variability, suggesting that the incidence of infectious diseases and virus transmission will only increase in the future. Therefore, more research needs to be done to improve understanding of climate change variations in bat distribution to prepare for potential bat-borne pandemics in the coming period.

*Important NOTE

bioRxiv publishes preliminary scientific reports that have not been peer-reviewed and therefore should not be relied upon as conclusive, to guide clinical practice/health-related behavior, or treated as established information.