Small round virus-like particles associated with acute gastroenteritis in japanese children

Nine patients with acute gastroenteritis shed small round virus-like particles in the faeces, and seven of them developed serum antibody against those particles as judged by immune electron microscopy. The small round virus-like particle was measured at 29–32 nm in diameter and showed a fine spiky structure on the surface. The buoyant density of the small round virus-like particles was determined to be 1.37–1.40 gm/cm3 in cesium chloride density gradient. The small round virus-like particle differed morphologically from astrovirus and calicivirus, and was antigenically dissimilar to Norwalk agent and W agent. These observations suggest that the small round vims-like particle is one of the new gastroenteritis viruses or may be a new serotype of them. Attempts to cultivate the small round virus-like particles were unsuccessful.