40-43-nm viruslike particles associated with gastroenteritis

By electron microscopy, 40-43-nm spherical viruslike particles were demonstrated in stools from gastroenteritis patients. The particles have 6-7-nm projections on the periphery and some of them show ringlike structures on their surface. Immune electron microscopy on paired sera and feces from one of the patients demonstrated preexisting antibody to the particles in acute-phase serum and an increase in antibody during illness.