Norovirus infection

Noroviruses are also called Norwalk-like viruses and caliciviruses. Noroviruses cause gastroenteritis, food infection, food poisoning, and acute nonbacterial gastroenteritis.

The symptoms of gastroenteritis caused by the noroviruses include nausea, vomiting, diarrhea, and abdominal (belly) pain. Diarrhea and vomiting can cause dehydration. You may have a headache and a fever. A mild and brief illness usually develops 24 to 48 hours after you eat or drink the contaminated food or water and lasts for 48 to 72 hours. Only in rare cases does a person get very sick or have to go to the hospital.

Most norovirus infections are mild and pass in a few days. So most people do not go to their doctors for a diagnosis. You can often diagnosis food poisoning yourself if others who ate the same food as you also become ill.

If you do go to your doctor, they will make the diagnosis based on your symptoms, a medical history, and a physical exam. Your doctor will ask where you have been eating and whether anyone who ate the same foods has the same symptoms. A stool test is sometimes done.

You treat gastroenteritis caused by noroviruses by managing complications until it passes. Dehydration caused by diarrhea and vomiting is the most common complication. Do not use medicines, including antibiotics and other treatments, unless your doctor recommends them.

To prevent dehydration, drink plenty of fluids. Choose water and other clear liquids until you feel better. You can take frequent sips of a rehydration drink (such as Pedialyte). Soda, fruit juices, and sports drinks have too much sugar and not enough of the important electrolytes that are lost during diarrhea. These kinds of drinks should not be used to rehydrate. In cases of severe dehydration, fluids may need to be replaced through an I.V. (intravenously).

When you feel like eating again, start with small amounts of food.

If you had diarrhea caused by norovirus, you should stay home for 2 to 3 days after your symptoms end before going back to work or school. This will help prevent spread of the virus.

There are things you can do to feel better. For example, drink plenty of fluids. Choose water and other clear fluids. You can take frequent sips of a rehydration drink (such as Pedialyte), but avoid soda, fruit juices, and sports drinks. When you feel like eating again, start with small amounts of food.