Discovery and current research status of feline morbillivirus

First report of feline morbillivirus in mainland China

Feline morbillivirus (FeMV) is an emerging member of the family Paramyxoviridae that is suspected to be involved in chronic kidney disease (CKD). FeMV was first discovered in Hong Kong in 2012 and has subsequently been detected in many countries. However, the prevalence of FeMV in mainland China is still unclear. To clarify the present status and examine the genetic diversity of FeMV in mainland China, in this study, we collected cat urine samples in veterinary hospitals in Guangdong Province in 2017 and 2018. Using reverse transcription (RT)-PCR, we found that the urine of six out of 64 cats tested positive for FeMV RNA. Sequencing and genetic analysis of the FeMV L gene showed that FeMV in mainland China is genetically diverse, and phylogenetic analysis showed that the viruses segregated into two clusters. Two isolates, GD5 and GD6, grouped in a branch that was separate from the one containing other previously reported FeMV isolates. These results will contribute to a better understanding of the evolution of FeMV in China.

Association of feline morbillivirus infection with defined pathological changes in cat kidney tissues

Feline morbillivirus (FeMV) is an emerging member of morbillivirus discovered in 2012. Although association of FeMV infection with kidney diseases in cats has been suggested, the pathogenicity of the virus has not been clear to date. To study the association between FeMV infection and pathological changes in kidney tissues of infected cats, we performed immunohistochemistry and immunofluorescent assays to detect FeMV antigens and analyzed the effect of FeMV infection on the pathological changes in the kidney tissues. In 38 kidney tissue samples from cats, some tissue injury scores were significantly higher when the FeMV antigens were detected, especially those for the tubular tissues in which the FeMV antigens were mostly localized. Pathological changes associated with the FeMV antigens included the ones typically found in chronic kidney diseases, such as interstitial cell infiltration, glomerulosclerosis, tubular atrophy and fibrosis. We also detected some feline IgG localizations in glomerular tissues, though co-localization or significant association with the FeMV antigens were not found. Our study confirms the association of FeMV infection with some kidney tissue injuries and provides additional information about roles of FeMV infection in chronic kidney diseases.