Definition:

Enteritis due to Norovirus is a major nonbacterial gastroenteritis worldwide. Norovirus is one of five genera of the family Caliciviridae of +ssRNA viruses. Human norovirus, previously known as Norwalk virus, was first identified during an outbreak of gastroenteritis in Norwalk, Ohio, USA. Noroviruses are currently categorized into at least seven genogroups (GI-GVII) that are further divided into more than 40 genotypes. Genogroup GI, GII, and GIV viruses infect humans. Human Noroviruses are primarily transmitted by the fecal-oral route, either by person-to-person contact, or by ingestion of contaminated food or water. Moreover, they significantly contribute to foodborne diseases.