Norovirus cause gastrointestinal illness to humans. Norovirus infection can cause vomiting, diarrhoea, and stomach pain. Less common symptoms are low fever, chills and headache. Vomiting can be sudden and frequent resulting in remarkable fluid loss. Death is rare but remains as a risk especially for elderly or persons with weakened immune system.

Recovery occurs usually in one or two days. The incubation period ranges between 12 and 48 hours. Sometimes, symptoms can be milder and last for a week but no long-term adverse health effects have been reported.