Communicable Disease Prevention and Control

Food and Water Borne Diseases

Noroviruses

Noroviruses are a group of viruses that cause the stomach flu, or gastroenteritis. The term norovirus is the official name for this group of viruses but they are also called Norwalk-like viruses (NLVs) and caliciviruses (because they belong to the virus family Caliciviridae).

The symptoms of norovirus illness usually begin suddenly and include nausea, vomiting, diarrhea, and stomach cramps. Sometimes, people have a low-grade fever, chills, headache, muscle aches, and fatigue. The symptoms usually last one to three days. Norovirus infections occur throughout the year but are more common in winter. All age groups are affected.

To learn more, please refer to the Noroviruses Fact Sheet or go to Public Health Agency of Canada Noroviruses - Fact Sheet web page.