Norovirus infection can cause severe diarrhea and vomiting. Noroviruses are a major cause of gastrointestinal illness in closed and crowded environments, such as hospitals, nursing homes and cruise ships.
Typically, people with norovirus infection develop diarrhea and abdominal pain and begin to vomit within 24 to 48 hours of exposure. Norovirus symptoms may last a few days, but most people recover completely without treatment. However, in some people — especially infants, older adults and people with underlying disease — vomiting and diarrhea can be severely dehydrating and require medical attention.
Norovirus infection is highly contagious. Noroviruses commonly spread through food or water contaminated by fecal matter during preparation. You can also acquire norovirus infection through close contact with an infected person — for instance, if you live in a nursing home or work in a day care facility.
Signs and symptoms of norovirus infection include:
The incubation period for norovirus infection is usually 24 to 48 hours after first exposure to the virus, and signs and symptoms usually 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 may unwittingly spread the virus to others.
When to see a doctor
Noroviruses are highly contagious and are shed in the feces of infected humans and animals. Oysters, salads and raspberries are among foods that have been responsible for outbreaks. Infected food handlers can transfer the virus to any food product just before it is served.
Methods of transmission include:
Noroviruses are difficult to eradicate, 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. In some cases, however, severe dehydration, malnutrition and even death can result from norovirus infection, especially among children and among older and immunocompromised adults in hospitals or nursing homes.
Preparing for your appointment
Most people don't need to seek medical attention for a norovirus infection, because it clears up on its own in a day or two. However, in cases involving infants, young children and older or immunocompromised adults, you may want to call your doctor if the illness lasts more than a few days or if it appears to be causing dehydration.
Warning signs of dehydration include:
What to expect from your doctor
Tests and diagnosis
Norovirus can be identified by testing a sample of your stool, but diagnosis is usually based on your symptoms alone.
Treatments and drugs
There's no specific treatment for norovirus infection, and recovery generally depends on the health of your immune system. In most otherwise-healthy people, the illness usually resolves within a few days.
The key factor is to replace lost fluids. If you're unable to drink enough fluids to prevent dehydration, you may need to receive fluids intravenously.
Lifestyle and home remedies
If your family includes young children, it's a good idea to have commercially prepared oral hydration solution, such as Pedialyte, on hand. Drinking liquids that contain a lot of sugar, such as soft drinks and many sports drinks, can make diarrhea worse.
Norovirus infection is highly contagious. Follow these suggestions to help prevent norovirus infection from spreading:
Last Updated: 2011-04-05
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