Each year in the USA, a wave of rotavirus illness begins in the Southwest in November and ends in the Northeast in March. Incubation is 1 to 3 days. Norwalk virus, the prototype calicivirus, most commonly infects older children and adults, and infections occur year-round. Incubation is 1 to 3 days. Adenovirus serotypes 40 and 41 are the second most common cause of childhood viral gastroenteritis.
Infections occur year-round, with a slight increase in summer.
Incubation is 8 to 10 days. Less is known about the epidemiology of non-Norwalk calicivirus and astrovirus. Both can infect persons of all ages but usually infect infants and young children. Calicivirus infections occur year-round, whereas gastroenteritis caused by astrovirus is most common in the winter. Transmission is via the fecal-oral route.