Investigation of SARS-CoV-2 in Zoos and Aquariums Using Serology and Biosecurity Assessments
Abstract
United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) reported 167 confirmed cases of SARS-CoV-2 (SCV2) in 13 zoo and aquarium species at 45 different zoos, aquariums, and sanctuaries in the United States.1 Testing was largely based on clinical signs and species’ susceptibility; the full range of species susceptible to SCV2 is unknown. In 2021, APHIS launched an investigation to better understand species’ SCV2 susceptibility, and biosecurity practices most effective at mitigating SCV2 transmission.2
Sixty facilities volunteered, providing serum samples collected before and during the pandemic—post-vaccination where possible—from 191 species. Samples were tested via SCV2 surrogate virus neutralization test (sVNT); additional tests were performed to distinguish vaccine response from virus exposure in vaccinated animals.
On-site biosecurity assessments conducted by APHIS veterinarians included a questionnaire, interviews, and tour. Additionally, 27 facilities participated in wildlife trapping to assess the risk of wildlife transmitting SCV2; blood samples were tested via sVNT; swabs were tested via RT-PCR.
For animals in human care, 1628 serum samples were tested from 835 animals, representing 191 species. Most vaccinated animals (191/234, 81.6%) seroconverted, and nine unvaccinated animals (12 samples) screened positive.
Wildlife trapping produced 1928 samples, representing 41 species. One sample from free-ranging wildlife was suspect positive; all remaining tested negative.
Biosecurity assessments identified common factors and practices that impacted mitigation of SCV2 spread.
Our findings further inform the zoo, aquarium, and wildlife communities of potential species’ SCV2 susceptibility and provide guidance for biosecurity measures to mitigate SCV2 spread.
Acknowledgements
The authors wish to thank all the participating facilities and their staff for their time and assistance with this project, and USDA students for assistance with data entry. The authors also thank and recognize the American Rescue Plan for funding this project.2
*Presenting author
Literature Cited
1. APHIS dashboard of confirmed cases of SARS-CoV-2 in animals. https://www.aphis.usda.gov/aphis/ourfocus/onehealth/one-health-sarscov2-in-animals. Accessed 3/24/2023.
2. USDA APHIS One Health webpage. https://www.aphis.usda.gov/aphis/ourfocus/onehealth/onehealth. Accessed 3/24/2023.