This virus renewed its fame in late 2002 as an agent of mass sickness on cruise ships. It is highly responsible for restaurant, hospital, and nursing home illness...the most common illness agent after the common "cold". Named after an outbreak in 1971 in Norwalk, Ohio, it is a "stomach bug" (upset stomach) causing nausea & vomiting, stomach cramps, and diarrhea...sometimes with headache and low-grade fever. The agent is actually a group of viruses called noroviruses. From contact to illness is 12-48 hours; illness lasts 12-72 hours. For the vast majority, illness is just a nuisance; can be fatal for infants and frail elderly through severe dehydration. It is extremely contagious!! Virus can live 5 or more days on surfaces of toys, etc.; and it is spread through touch, food & water, and aerosolized from vomiting.

If a patient has high fever, blood-tinged diarrhea stool, or is among numerous people from a group needing hospitalization, it may be a bacterial illness (salmonella, shigella, or E. coli). Stool culture tests detect those bacteria; there are tests for Norwalk (but usually not needed).

(posted 21 December 2002)