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

Gnotobiotic newborn calves were found to be susceptible to infection with the reovirus-like agent of human infantile gastroenteritis (HRVL). Infection was based on (i) seroresponse using immunofluorescence and (ii) fecal shedding of virus particles using electron microscopy. Virus was detected in fecal samples for at least 2 to as long as 7 days after inoculation, although peak virus concentrations were observed on days 1 to 4.

Immune response to orally administered calf reovirus-like agent and coronavirus vaccine.

Twenty 6-to 7-hour-old gnotobiotic calves inoculated orally with attenuated calf diarrhea reovirus-like agent and challenge-inoculated with virulent virus 48-72 h post-inoculation (PI) remained clinically normal during the post-vaccination observation period; one developed mild diarrhea after challenge inoculation. Four non-vaccinated challenge control calves developed severe diarrhea. Twenty 6-to 7-hour-old gnotobiotic calves inoculated orally with attenuated calf diarrhea coronavirus and challenge inoculated with virulent virus 96 h later remained clinically normal during the post-vaccination and post-challenge observation period.