Molecular epidemiology of astroviruses in Japan from 1995 to 1998 by reverse transcription-polymerase chain reaction with serotype-specific primers (1 to 8).

In addition to the serotype-specific primers described previously (1 to 7), a new serotype 8-specific primer has been designed, allowing detection of all astrovirus serotypes. A total of 1,382 diarrheal stool samples in 5 regions in Japan were examined by reverse transcription-polymerase chain reaction (RT-PCR). The incidence of astrovirus infection in all 5 regions was 5.9% (82 of 1,382 samples) and infection occurred mainly from November to April. Serotypes 1, 3, and 4 were detected in 66, 14, and 2 of the 82 positive samples, respectively. None of the other serotypes was detected. The highest detection rate was from 0 to 1 year old, 39.0%, and the next highest was from 1 to 2 years old, 34.1%. The primers provide a useful approach for study of the epidemiology of astroviruses.