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 during preparation or contaminated surfaces. You can also be infected through close contact with an infected person. Diarrhea, abdominal pain and vomiting typically begin 12 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, child care centers, schools and cruise ships.
Signs and symptoms of norovirus infection include:
Signs and symptoms usually begin 12 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 two weeks after recovery. Viral shedding may last several weeks to several months if you have an underlying health condition. Some people with norovirus infection may show no signs or symptoms. However, they are still contagious and can spread the virus to others.
Seek medical attention if you develop diarrhea that doesn't go away within several days. Also call your doctor if you experience severe vomiting, bloody stools, abdominal pain or dehydration.
Noroviruses are highly contagious and are shed in the feces of infected humans and animals. Methods of transmission include:
Noroviruses are difficult to wipe out because they can withstand hot and cold temperatures as well as most disinfectants.
Risk factors for becoming infected with norovirus include:
For most people, norovirus infection clears up within a few days and isn't life-threatening. But in some people — especially children and older adults with compromised immune systems in hospitals or nursing homes — norovirus infection can cause severe dehydration, malnutrition and even death.
Warning signs of dehydration include:
Children who are dehydrated may cry with few or no tears. They may also be unusually sleepy or fussy.
Norovirus infection is highly contagious, and anyone can become infected more than once. To help prevent its spread:
There's no specific treatment for norovirus infection, and recovery generally depends on the health of your immune system. In most people, the illness usually resolves within a few days. It's important to replace lost fluids. If you're unable to drink enough fluids to prevent dehydration, you may need to receive fluids intravenously.