Norovirus is the most common cause of non-bacterial foodborne illness and gastroenteritis each year, with more than 685 million cases typically reported each year. One out of every five cases of acute gastroenteritis (inflammation of the stomach or intestines) that leads to diarrhea and vomiting is caused by norovirus. It is easily spread from infected people, contaminated foods, water, or by touching contaminated surfaces.
Typical symptoms include fever, headache, body aches, loss of taste, dizziness, decrease in urination, stomach pain, nausea, diarrhea, and vomiting. Anyone can be infected with norovirus, but young children, pregnant women, the elderly, and immunocompromised people are most at risk.