Molecular Epidemiology and Risk Analysis for Asymptomatic Infection with Feline Enteric Coronavirus in Domestic and Stray Cats in Japan

Abstract

Abstract Feline coronavirus is classified into two coronaviruses: feline enteric coronavirus (FECoV) and feline infectious peritonitis (FIP) virus (FIPV), which cause mild diarrhea and deadly peritonitis in cats, respectively. Since FIPV arises by mutation(s) in FECoV, a survey of FECoV infection in cats is needed to provide fundamental information for prevention of FIP. FECoV also causes subclinical infection; therefore, asymptomatic cats may play a role as a reservoir and transmitter of FECoV. However, there is limited information on the prevalence of FECoV and information from risk analysis of asymptomatic FECoV infection in healthy cats. We conducted a molecular survey of FECoV in normal feces from healthy domestic and stray cats by using nested RT-PCR targeting the FECoV S gene. Interestingly, the RT-PCR-positive rate in domestic cats (35.5%) was significantly higher than that in stray cats (15.9%). Our risk analysis revealed that age less than 1 year and keeping cats indoors are risk factors of asymptomatic FECoV infection. Furthermore, a phylogenetic tree based on partial FECoV S genes suggested transmission of FECoV between domestic cats and stray cats. Our data will contribute to a better understanding of the ecology of FECoV in healthy cats for prevention of FIP.