Spatial and temporal clustering of anti-SARS-CoV-2 antibodies in Illinois household cats, 2021-2023

This study evaluated the seroprevalence of SARS-CoV-2 antibodies in Illinois household cats from October 2021 to May 2023. Among 1,715 samples tested by serological assays, 244 samples (14%) tested positive. High-rate temporal, spatial, and space-time clusters of SARS-CoV-2 cases were assessed within 63 counties in Illinois. Three space-time clusters with higher than expected seroprevalence rates were identified in the northeastern, central-east, and southwest regions of Illinois, occurring between June and October 2022. Young cats had a higher seropositivity than older cats, and the third quarter of the year had the highest odds of seropositivity . This study provides an in-depth analysis of SARS-CoV-2 epidemiology in Illinois household cats, which will aid in COVID-19 control and prevention. Article summary line SARS-CoV-2 antibody seroprevalence was assessed in Illinois domestic cats, in which a higher seropositivity rate was clustered in the northern, central, and southern Illinois regions with peak periods occurring between June and October 2022. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This project was supported by the National Institute of Health [Grant# R01AI166791, to Y. Fang (PI) and D. Diel (MPI)]. ### 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: https://dph.illinois.gov/covid19/data/surveillance.html I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the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, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.