ASTROVIRUS AS A CAUSE OF GASTROENTERITIS IN JAPAN

We used an enzyme immunoassay (EIA) to screen for astrovirus in stool specimens from outbreaks and sporadic cases of gastroenteritis collect ed between 1982 and 1992 in six prefectural public health institutes i n Japan. Three outbreaks of gastroenteritis involving schoolchildren a nd adults were confirmed to be attributable to astrovirus. Astrovirus was detected in 6 to 10% of the specimens from patients with sporadic gastroenteritis from whom no other bacterial or viral agent had been i dentified. Among the sporadic cases, astrovirus was most frequently de tected in infants less than 1 year of age, and the incidence peaked in March and April. Using specimens from recent outbreaks, eve found tha t the EIA was more sensitive than electron microscopy (EM) for the det ection of astrovirus, and many EM-negative specimens were positive by EIA. However, some stool specimens previously found to have astrovirus -like particles by EM were negative by EIA, perhaps because of inadequ ate storage conditions, such as long-term storage and repeated freezin gs and thawings. Our results indicate that astrovirus is more commonly associated with childhood gastroenteritis than has been previously ap preciated and suggest that further studies to examine the epidemiology and disease burden of this virus are needed.