Abstract
Results of serotyping on 291 astrovirus-positive stools collected between 1976 and 1992 showed that about two-thirds (64.9%) were serotype 1. Infections were more frequent in the fourth quarter of the year and there was a suggestion that during the past 5 years serotype 1 has occurred with greater frequency in alternate years. Evidence is provided for the existence of two new serotypes, 6 and 7.