Seroprevalence of Coronaviruses FCoV and SARS-CoV-2 in domestic cats in Kerala

Seroprevalence of Feline coronavirus (FCoV) and Severe acute respiratory syndrome coronavirus-2 (SARSCoV- 2) were analysed in a set of serum samples collected from domestic cats presented to tertiary care veterinary clinics during the first COVID pandemic wave in Thiruvananthapuram in 2021. In 156 samples analysed, virus-specific indirect ELISA detected the presence of FCoV antibodies in 72 samples (46.2 per cent) and SARS-CoV-2 antibodies in 12 samples (7.7per cent). Among the samples showing seropositivity for FCoV, 3.84 per cent had a significantly high antibody titre exceeding 1:6400 indicating the possible prevalence of Feline infectious peritonitis virus (FIPV), a serious and often fatal disease arising from mutations in FCoV. Among the 12 SARS-CoV-2 positive samples, six exhibited ability to neutralise SARS-CoV-2 pseudovirion infectivity, further confirming the specificity of the detection. Our data did not exhibit significant cross-reactivity between SARS-CoV-2 and FCoV antibodies. Even though there is no confirmed SARS-CoV-2 transmission from cats to humans, domestic cats may act as reservoirs, facilitate reverse zoonotic events and possibly promote viral mutations. Our observations reiterate the need of one health approach to prepare better for zoonotic threats and future pandemics.