Seasonal trend and serotype distribution of rotavirus infection in Japan, 1981-2008.

A total of 10,917 fecal specimens from infants and children with gastroenteritis in seven different regions of Japan in the last 3 decades were examined for rotavirus. We observed that the rotavirus peak shifted gradually from January to April (winter to early spring) during 17 seasons and the G1P[8] combination was the most predominant genotype in the last 28 years in Japan.