Probable transmission of SARS-CoV-2 from an African lion to zoo employees

Animal to human transmission of SARS-CoV-2 has not previously been reported in a zoo setting. A vaccinated African lion with physical limitations requiring hand feeding tested positive for SARS-CoV-2 after development of respiratory signs. Zoo employees were screened, monitored prospectively for development of symptoms, then re-screened as indicated, with confirmation by RT-PCR and whole-genome virus sequencing when possible. Trace-back investigation narrowed the source of infection to one of five people. Three exposed employees subsequently developed symptoms, two with viral genomes identical to the lion’s. Forward contact tracing investigation confirmed probable lion-to-human transmission. Close contact with large cats is a risk factor for bidirectional zoonotic SARS-CoV-2 transmission that should be considered when occupational health and biosecurity practices at zoos are designed and implemented. SARS-CoV-2 rapid testing and detection methods in big cats and other susceptible animals should be developed and validated to facilitate timely implementation of One Health investigations. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The study did not receive any funding. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors