Overview
Norovirus infection can cause severe vomiting and diarrhea that start suddenly. Noroviruses are highly contagious. They commonly spread through food or water that is contaminated during preparation or through contaminated surfaces. Noroviruses can also spread through close contact with a person who has norovirus infection.
Diarrhea, stomach pain and vomiting typically begin 12 to 48 hours after exposure. Norovirus infection symptoms usually last 1 to 3 days. Most people recover completely without treatment. However, for some people — especially young children, older adults and people with other medical conditions — vomiting and diarrhea can be severely dehydrating and require medical attention.
Norovirus infection occurs most frequently in closed and crowded environments. Examples include hospitals, nursing homes, child care centers, schools and cruise ships.
Symptoms
Signs and symptoms of norovirus infection may start suddenly and include:
- Nausea
- Vomiting
- Stomach pain or cramps
- Watery or loose diarrhea
- Feeling ill
- Low-grade fever
- Muscle pain
Signs and symptoms usually begin 12 to 48 hours after your first exposure to a norovirus and last 1 to 3 days. You can continue to shed virus in your stool for several weeks after recovery. This shedding can last weeks to months if you have another medical condition.
Some people with norovirus infection may show no signs or symptoms. However, they're still contagious and can spread the virus to others.