Small spherical viruses in faeces from gastroenteritis patients.

Faecal samples from 238 patients with gastroenteritis were examined by direct electron microscopy using grids with thin carbon film. Of these samples 18 were found to contain Norwalk agent-like particles, calicivirus, astrovirus and parvovirus-like particles. Immune electron microscopy was performed on a serum pair and faeces from one of the patients with astrovirus. An antibody response was demonstrated, suggesting that the virus was the etiological agent of the infection.