In the United States, the peak incidence of rotavirus diarrhea is among children 6 months-2 years of age, although in developing countries younger infants may be affected. By 4 years of age, most persons have been infected and are immune to the severe dehydrating syndrome, but a high inoculum or lowered immunity can produce milder illness among older children or adults. One-third of parents whose children are infected with rotavirus become ill, and rotavirus diarrhea can occur among travelers to developing nations, the elderly, and persons with debilitative or immunosuppressive conditions. In general, the incubation period for Rotavirusis approximately 2 days and is followed by vomiting for 3 days and watery diarrhea for 3-8 days. Fever and abdominal pain occur frequently.
Many children can shed rotavirus and never become ill.
When food or water is contaminated to the extent that it overcomes adult immunity, rotavirus diarrhea among adults may be relatively common. Immunity Infection generally confers long-term immunity to serious gastroenteritis, but asymptomatic or minimally symptomatic reinfection can occur throughout life. Immunity may wane among the elderly, rendering them susceptible again to severe disease. In the United States, illness is most commonly reported among persons of school age and older. Nausea is prominent, with vomiting, non-bloody diarrhea, and abdominal cramps occurring in most cases.