How common is Norwalk virus infection?
Norwalk and Norwalk-like viruses are increasingly being recognized as leading causes of foodborne disease in the United States. However, since no routine diagnostic test is available, the true prevalence is not known. Norwalk and Norwalk-like viruses have been linked to outbreaks of intestinal illness on cruise ships and in communities, camps, schools, institutions, and families. Many oyster-related outbreaks of intestinal illness linked to Norwalk-like viruses have been reported in Louisiana, Florida, Maryland, and other states where oyster harvesting is common. In 1993, 73 people in Louisiana and about 130 others in the United States who ate oysters from Louisiana became ill. A malfunctioning sewage system was the cause of an outbreak in 1996. An outbreak in 1997 was linked to sewage from oyster-harvesting boats. How can Norwalk virus be prevented? • Wash hands with soap and warm water after toilet visits and before preparing or eating food. • Cook all shellfish thoroughly before eat
