Norovirus

Norovirus infection can cause the sudden onset of severe vomiting and diarrhea. The virus is highly contagious and commonly spread through food or water that is contaminated by fecal matter during preparation. You can also be infected through close contact with an infected person. Diarrhea, abdominal pain and vomiting typically begin 24 to 48 hours after exposure. Norovirus symptoms last one to three days, and most people recover completely without treatment. However, for some people — especially infants, older adults and people with underlying disease — vomiting and diarrhea can be severely dehydrating and require medical attention. Norovirus infection occurs most frequently in closed and crowded environments such as hospitals, nursing homes, schools and cruise ships.

Symptoms

Signs and symptoms of norovirus infection include:

  • Nausea
  • Vomiting
  • Abdominal pain or cramps
  • Watery or loose diarrhea
  • Malaise
  • Low-grade fever
  • Muscle pain
  • Signs and symptoms usually begin 24 to 48 hours after first exposure to the virus, and last one to three days. You may continue to shed virus in your feces for up to three days after recovery.

Some people with norovirus infection may show no signs or symptoms. However, they are still contagious and can spread the virus to others.

Causes

Noroviruses are highly contagious and are shed in the feces of infected humans and animals. Methods of transmission include:

  • Eating contaminated food
  • Drinking contaminated water
  • Touching your hand to your mouth after your hand has been in contact with a contaminated surface or object
  • Being in close contact with a person who has a norovirus infection
  • Noroviruses are difficult to wipe out because they can withstand hot and cold temperatures as well as most disinfectants.