[Epidemiology of rotavirus infection around Tokyo area].
ABSTRACT Epidemiology of rotavirus infection was studied from 1981 to 1988 mainly in three hospitals around Tokyo area. Major serotypes of rotaviruses in the three places were different from those in two hospitals around Kansai area in Japan (Ref. 6, 13), while, major serotypes were same among three hospitals. Both of serotypes 1 and 4 in group A were mostly found around Tokyo area. Frequencies of type 2, 3, and 9 in group A were low, although the frequencies were various among periods. Detail examinations of rotavirus RNA electropherotypes showed the results as follows; different electropherotypes were found during one winter season and at one hospital, the identical electropherotype was found cross a year and cross a hospital. We could not find the identical electropherotype which belong to two serotypes so far. Seven group C rotaviruses were found since 1987 in three hospitals. It would be important to examine RNA electropherotypes and serotypes for long period not only for epidemiological studies but also for development of vaccine.