ABSTRACT
Norwalk virus originated from an outbreak of nonbacterial gastroenteritis that occurred in a school in Norwalk, Ohio. Norwalk virus has the appearance of a small round structured virus and is the prototype of the group. Members of the Norwalk virus group have tended to be named after the geographic location of the incident in which they were identified. The pathogenic mechanisms of the Norwalk group viruses are poorly understood. Norwalk virus appears to infect mature enterocytes of the proximal small intestine. Norwalk virus induces production of both local gut and serum antibody. Various small round viruses in the size range of 20–40 nm may be found in feces; some of these have been associated with gastroenteritis. Norwalk and Norwalk-like viruses are the most common cause of foodborne viral illness. Control of foodborne viral illness depends largely on strict attention to normal good hygienic practice in the kitchen and serving areas.
