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.
Noroviruses are spread mainly through contact with the vomit or feces of an infected person. This happens because:
It is important to wash hands carefully even after symptoms stop.
There are no medications to treat this infection. Drink plenty of fluids to prevent dehydration. See a doctor if vomiting or diarrhea lasts for more than 2 to 3 days. Healthy people usually recover on their own in about 48 hours.