Existence of feline morbillivirus infection in Japanese cat populations.

Feline morbillivirus (FmoPV) is a member of a new virus species that has only been found in the Hong Kong cat population. For the first time, however, we have now detected nucleotide sequences similar to FmoPV in samples from Japanese cat populations. The positive rates for urine and blood samples from Japanese cats were 6.1 % (5/82) and 10 % (1/10), respectively. These sequences are similar to the previously reported FmoPV, with 92-94 % identity, and substantially different from all other morbilliviruses. Phylogenetic analysis of the identified Japanese FmoPVs and other morbilliviruses demonstrated a pattern similar to those previously published for the FmoPV viruses isolated in Hong Kong. FmoPV RNA was also detected from formalin-fixed paraffin-embedded (FFPE) kidney tissues of cats with nephritis, with a positive rate of 40 % (4/10). By using nested-set primers based on the FmoPV sequence and RNA from FFPE tissues, we demonstrated the existence of FmoPV infection in Japanese cats and established the method for detection of the FmoPV RNA from kidney tissues prepared for pathology examinations, which is useful for studies on the pathogenicity of the virus.