Outbreaks of gastroenteritis caused by SRSVs from 1987 to 1992 in Kyushu, Japan: Four outbreaks associated with oyster consumption

From 1987 to 1992, 18 outbreaks of acute non-bacterial gastroenteritis occu rred in Kyushu district. The most common symptoms were diarrhea, vomiting, nausea and abdominal cramp. Small round structured viruses (SRSVs) were det ected in 52 (44.8%) of 116 stool samples from 17 outbreaks by the electron microscopy (EM) method, and a significant increase in the antibody level wa s noted in 42 (80.7%) of 52 paired serum samples from 12 outbreaks by the i mmune electron microscopy (IEM) method and in 18 (51.4%) of 35 samples from 8 outbreaks by the western blot (WB) method. However, according to the WE method, antigen-antibody reaction was not observed to reference antigen str ips (SRSV-9/Tokyo 86-510, 63 kDa) in three of the 8 outbreaks, The detected virus was regarded as an etiologic agent for these outbreaks. In four of 5 outbreaks which appeared associated with eating raw oysters, there was a c lose relation between SRSV infection and consumption of raw oysters.