Detection in Japan of an equine-like G3P[8] reassortant rotavirus A strain that is highly homologous to European strains across all genome segments.

Equine-like G3P[8] rotavirus A strains with DS-1-like backbone genes have emerged since 2013. An equine-like RVA/Human-wt/JPN/15R429/2015/G3P[8] strain possessing I2-R2-C2-M2-A2-N2-T2-E2-H2 was detected in Japan in 2015. Its VP7 gene was ≥ 99.3% identical to those of equine-like G3P[4] strains detected in Japan, and the remaining 10 genes were 98.6-99.8% identical to G1P[8] double-gene reassortants detected in Japan, Thailand and the Philippines. Thus, 15R429 was likely generated through reassortment between the equine-like G3P[4] and G1P[8] reassortant strains. Notably, 15R429 was 98.5-99.8% identical across all 11 genes of the equine-like G3P[8] strains detected in Spain and Hungary in 2015.