Generally, group A rotaviruses are the most common cause of paediatric diarrhoea. However, group B rotavirus, adult diarrhoea rotavirus (ADRV), was found to be involved in epidemics of severe gastroenteritis in several areas of China during 1982–1983 and had resulted in more than one million cases among adults as well as older children. Human group B rotavirus has been rarely reported outside China, but has been detected first from five adults with diarrhoea in Kolkata, India during 1997–1998 (strain CAL-1). During epidemiological studies at the National Institute of Virology (NIV) on hospitalized diarrhoea patients at Pune, India, faecal specimens from patients of >5 years age, which were negative for group A rotavirus by ELISA were tested by polyacrylamide gel electrophoresis (PAGE). We detected rotavirus RNA migration patterns similar to that of group B rotavirus in three faecal specimens from adults, two from the specimens collected in 1993 and one in 1998 from sporadic diarrhoea cases. RT–PCR was carried out using primers derived from gene 8 which codes for the NS2 protein, followed by nested PCR, which confirmed the presence of group B rotavirus in all three specimens. The sequences of the PCR products of NIV specimens were compared with that of CAL-1, ADRV and IDIR (infectious diarrhoea of infant rat) belonging to group B rotaviruses. The sequence analysis of the PCR products showed the highest identity with CAL-1, which was reported from Kolkata, India during 1997–1998. The finding suggests that human group B rotaviruses have been circulating in Pune, India, since 1993. This emerging virus may lead to more severe disease among adults in India. There is a need for surveillance of group B rotavirus infections, especially in adult diarrhoea cases and seroepidemiological studies on group B rotavirus are required among humans and animals of Western Maharashtra, India.
Survey of Human Group C Rotaviruses in Japan during the Winter of 1992 to 1993
