An outbreak of acute gastroenteritis caused by human group C rotavirus in a welfare institution in Okayama prefecture.

Rotaviruses are members of the Reoviridae family and are recognized as important causative agents of acute gastro-enteritis. The genomes of rotaviruses consist of 11 segments of double-stranded RNA (dsRNA) enclosed in double-shelled particles. Rotaviruses are classified into at least seven groups (groups A-G) on the basis of their dsRNA electropherotypes and a common group antigen on the inner capsid protein (1, 2). Three of these groups (A, B and C) are known to infect humans (1,2). Several outbreaks of acute gastroenteritis caused by human group C rotavirus (CHRV) have been reported in Japan (3-9). Most of these outbreaks occurred in school-aged people aged 6 to 18 years. Generally, an outbreak of CHRV