Intestinal lesions induced in gnotobiotic calves by the virus of human infantile gastroenteritis.

Four gnotobiotic calves with intestinal lesions induced by third and fourth calf passages of virus of human infantile gastroenteritis were studied by light microscopy, scanning and transmission electron microscopy, and by immunofluorescence. Calves, 25--72 hours old, were examined 0.5 hours, 3 hours, 7 hours, and 48 hours after the onset of diarrhea. Intestinal histology of infected calves was compared to that of two noninoculated gnotobiotic calves 48 and 72 hours old. The sequence of events in the small intestine was infection of the absorptive villous epithelial cells, replacement of the tall columnar villous epithelial cells with cuboidal and squamous cells, shortening of the villi, enlargement of reticular cells, lymphocytic infiltration of the villous lamina propria and repair.