Effects of environmental and dietary factors on human rotavirus infection in gnotobiotic piglets.

The addition of proteolytic enzyme to diets fed to newborn gnotobiotic piglets exacerbated their diarrheal response after oral infection with human rotaviruses. Supplementation of diets with proteolytic enzyme and reduced ambient temperature were evaluated for effects upon the clinical response of gnotobiotic piglets infected with human rotavirus Wa strain, type 2. Piglets were divided into four treatment groups combining two variables: ambient temperature of 35 or 26 degrees C, with and without proteolytic enzyme supplementation of the diet. Infected piglets maintained at 26 degrees C with and without enzyme supplementation had 90 and 70% mortality, respectively. No mortality was observed in infected piglets maintained at 35 degrees C. Protease supplementation of diets fed to piglets kept at 35 degrees C resulted in more uniform onset of diarrhea of greater severity than in littermates fed diets without the supplementation.