Risks posed by SARS-CoV-2 to North American bats during winter fieldwork

Area of Science:

• Veterinary Science
• Wildlife Disease Ecology
• Epidemiology

Background:

• The origin of SARS-CoV-2 in bats raises concerns about reverse zoonotic transmission from humans to bats.
• Wildlife management agencies are evaluating risks associated with human activities and potential SARS-CoV-2 transmission to bat populations.
• Previous assessments indicated a risk during summer fieldwork, necessitating updated evaluations for winter conditions.

Purpose of the Study:

• To assess the risk of SARS-CoV-2 transmission from humans to North American bats during winter fieldwork.
• To evaluate the impact of factors such as fieldwork type, environmental conditions, and human precautions on transmission risk.
• To inform wildlife management and research practices to minimize potential zoonotic disease spread.

Main Methods:

• Utilized an aerosol transmission model incorporating literature-based parameters and expert judgment.
• Estimated transmission risk for three species of North American bats.
• Analyzed the influence of chamber volume, local COVID-19 prevalence, and mitigation strategies.

Main Results:

• Transmission risks to bats during winter fieldwork are lower than previously estimated.
• Key factors influencing transmission risk include the volume of enclosed spaces and the prevalence of COVID-19 in the local human population.
• High-filtration facemasks and pre-fieldwork negative COVID-19 tests reduced zoonotic risk by 65-88%.

Conclusions:

• Winter fieldwork poses a reduced risk of SARS-CoV-2 transmission to bats compared to summer.
• Implementing specific precautions during fieldwork is crucial for mitigating the risk of human-to-bat virus transmission.
• Further research and monitoring are needed to manage potential disease spillover events in wildlife populations.