Viral hepatitis and gastroenteritis transmitted by shellfish and water.

The epidemiology and clinical presentation of water-borne viral diseases, including shellfish-associated viral illnesses, are discussed in this article. Hepatitis A virus, Non A-Non B hepatitis and the agents of viral gastroenteritis, Norwalk agent, Snow Mountain agent, rotavirus, the small round viruses, caliciviruses, and astroviruses are included. The technical problems associated with evaluating the viral contamination of water or shellfish are noted.