Control of food-borne viruses

There are two main food-borne virus infections. These are viral gastroenteritis caused by small round structured viruses (SRSV) of the Norwalk group and hepatitis A. Both infections are normally transmitted directly from person-to-person, but on occasions they may also be food-borne or water-borne. Viruses do not multiply or produce toxins in foods, and foods merely act as vehicles for their passive transfer. Foods may be contaminated by infected food-handlers, and outbreaks frequently involve cold foods that require much handling during preparation. Foods may also be contaminated in their growing and harvesting areas by sewage polluted water, and molluscan shellfish have been particularly implicated. PCR and ELISA based methods are being developed for detection and typing of viruses in patients and also in food samples. Sensitive detection methods should facilitate the design of improved food processing methods to ensure virus-free food.