Epidemic, 1/2 of all nonbacterial epidemics; spread by fecal—oral route, eg, contaminated oysters (Jama 1995;273:466); a calcivirus
Sx:Incubation period 24-48 h
Si: No fever, no fecal leukocytes present, vomiting > diarrhea in children, reverse in adults, big issue in NHs; r/o other viral gastroenteritis causes (Nejm 1991;325:252) including rotavirus, enteric adenovirus, and astrovirus, esp in small children (Nejm 1991;324:1757)