Feline Circovirus-1 in domestic cats: A multicentric European epidemiological study

Members of the family Circoviridae (circovirids) have been identified in several animal species and in human specimens. Circoviruses (CVs) are pathogenic for swine and birds whilst they have been associated with gastro-intestinal, respiratory disorders and systemic disease in dogs. Recently, a novel feline CV (FeCV-1) has been identified as a predominant circovirus population in fecal samples of cats in a study in Italy. To better assess the circulation of FeCV-1 in the feline population, in the present study, we investigated the prevalence of FeCV-1 in samples (rectal and oropharyngeal swabs, and blood) of domestic cats collected from Greece, Romania, and Portugal. A quantitative PCR assay specific for FeCV-1 was used for molecular screening. Overall, 22 (11.8 %) out of 187 samples tested positive for FeCV-1 with a prevalence of 20.4 % (10/49) in Greek samples, 15.9 % (7/44) in Romanian samples, and 5.4 % (5/94) in Portuguese samples. FeCV-1 was detected in both fecal and respiratory samples. The whole genome sequence was determined for eight variants. The FeCV-1 genomes determined in this study shared 95.2 % to 99.6 % nt identity to the initial variants (OQ357577 -OQ357579) detected in Italy, forming a well-conserved clade. These findings suggest that FeCV-1 is a common component of the feline virome. Understanding the pathogenic role, if any, of FeCV-1 in cats will be necessary in prospective studies.