Norovirus is caused by a highly contagious virus that spreads primarily through accidental ingestion of tiny particles of feces or vomit from an infected person. It can be transmitted by:
- Consuming contaminated food or water (e.g., food handled by infected persons or seafood like oysters grown in contaminated water).
- Touching contaminated surfaces or objects and then touching the mouth.
- Close contact with someone infected.
- Airborne particles from vomit can also contaminate food or surfaces.
Only a few virus particles are needed to cause infection, and the virus is shed in large quantities from infected individuals, making it very easy to spread. Norovirus causes inflammation of the stomach and intestines, leading to symptoms like vomiting and diarrhea, typically starting 12 to 48 hours after exposure.
