Detection and genetic characterization of enterovirus strains circulating among children with acute gastroenteritis in Japan during 2014-2016

Of 972 stool samples collected from infants and children with acute gastroenteritis in six different regions (Hokkaido, Tokyo, Shizuoka, Kyoto, Osaka, and Saga) of Japan during 2-year period from July 2014 to June 2016, 63 samples (6.5%) determined to be positive for enterovirus by multiplex RT-PCR were subjected to genotype determination based on the partial VP1 region using the CODEHOP method. Sixty-two strains were succeeded in genotyping and seventeen EV types were identified. The majority of the studied strains belonged to EV-A (30 of 62; 48.4%) and EV-B (31 of 62, 50%) species, and the remaining strain was of the EV-D species. The most frequently detected type was Coxsackievirus A5 (CV-A5) in 2014-2015 while was CV-B5 in 2015-2016. This study provides an insight into the genetic diversity of EV with the predominance of EV-A and EV-B species in Japanese infants and children with acute gastroenteritis during 2014-2016.