ABSTRACT
Foodborne or waterborne disease is defined by the World Health Organization as "a disease of an infectious or toxic nature caused by, or thought to be caused by, the consumption of food or water". Compared to other foodborne diseases, those caused by viruses are less severe and seldom fatal. Foodborne disease has been estimated that no more than 10% of the cases of all foodborne illness are reported to official agencies. In viral foodborne disease outbreaks, where different transmission routes may be possible at the same time, the distinction between food- and waterborne transmission and any person-to-person spread is difficult. Most foodborne viruses infect their host per orally by ingestion and are subsequently shed. For reasons enumerated above, epidemiological investigations and surveillance of food-borne viral diseases cannot be conducted on a routine basis in most countries. Norwalk and Norwalk-like viruses have been associated with epidemic viral gastroenteritis in the United States.
