Abstract

Noroviruses (formerly known as Norwalk-like viruses) can cause large outbreaks of gastrointestinal disease in humans. Infection with norovirus is commonly characterised by a sudden onset of diarrhoea and/or vomiting, lethargy, headache, abdominal discomfort, nausea, anorexia, and fever. Symptoms start about 12–36 hours after a person acquires the infection and usually resolve within 72 hours. Most people recover with rest; however, symptoms can sometimes be severe and require treatment in hospital. Illness often results in working days lost and other costs.