Detection of kobuvirus RNA in Japanese domestic dogs

SOMA, Takehisa; MATSUBAYASHI, Makoto; SASAI, Kazumi

Yamashita et al. [28] isolated a large amount of viral RNA similar to that of CaKoV from sludge obtained from a wastewater treatment plant. We found that the sewage virus had a very high homology with CaKoV detected in the dogs of the present study, indicating a possible canine origin. As noted above, CaKoV tends to be epidemic in an environment where several dogs are kept together. However, the risk of CaKoV infection even in a dog-free environment is under- standable, since picornaviruses are highly stable in a normal environment. Phylogenetic tree analysis of the 3D region showed that the viral strains isolated in Japan including CaKoV from sewage sludge could be classified into the same clade as those found in countries neighboring Japan, such as Korea and China, but into a different clade as compared to those isolated in Europe, the United States and Africa, if subdivided. Thus, CaKoV may be specific to various countries and regions, and may show independent transmission.