9.4.2  Viral infections

Several different viruses may be transmitted by contaminated food via the faeco-oral route. Foodborne viral infections usually have an incubation period of between one and three days. They cause illnesses which are self-limited in people who are otherwise healthy (i.e. they recover naturally) but occasionally severe illness and even deaths may also occur.

In the group of viral infections causing viral gastroenteritis (VGE), rotavirus is a common cause of vomiting and watery diarrhoea. Dehydration is the likely consequence unless appropriate rehydration therapy is used. Caliciviruses such as norovirus (also known as Norwalk virus) also cause diarrhoea.

Viral hepatitis caused by Hepatitis A and E viruses is almost exclusively transmitted by the faeco-oral route. Hepatitis A is distinguished from other viral causes by its prolonged (two to six weeks) incubation period and its ability to spread beyond the stomach and intestines into the liver. It often induces jaundice, or yellowing of the skin, and can occasionally lead to chronic liver dysfunction.