Diarrhea caused in gnotobiotic piglets by the reovirus-like agent of human infantile gastroenteritis.

One- to four-day-old gnotobiotic piglets were inoculated orally with a reovirus-like agent obtained from human infants with acute gastroenteritis. Diarrhea developed in the piglets two to seven days after inoculation and was reproduced for five serial passages in one sequence and for three passages in another. Nineteen of 21 inoculated piglets developed diarrhea; reovirus-like particles were observed in intestinal contents and/or fecal samples from 17 animals with illness and from two inoculated piglets that did not develop diarrhea. One piglet, for which daily fecal samples were examined by electron microscopy, shed the largest number of virus particles at the onset of diarrhea. Immunofluorescent antibody responses to the reovirus-like agent were detected in sera from the seven inoculated animals that were tested.