You thought the illnesses of winter had ended. Your family’s final round of influenza, strep throat and the common cold are gone. But stomach viruses still are lurking.

Although they are known as the “stomach flu,” stomach viruses are not caused by the flu virus (influenza). The flu shot does not protect people from catching the “stomach flu.”

Stomach illness are caused by norovirus, rotavirus and others. Symptoms include vomiting, diarrhea, fever, cramping, chills, headache, fatigue and dehydration.

Rotavirus usually sickens children under age 2. A rotavirus vaccine is given to infants at 2, 4 and 6 months of age. It protects children against five types of rotavirus.

Norovirus is the main cause of illness from contaminated food. About half of all outbreaks from food are caused by norovirus, according to the Centers for Disease Control and Prevention. Lettuce and leafy greens, fresh fruits, ice and shellfish are most often blamed, but any food can become contaminated.

Norovirus is difficult to kill and spreads easily in crowded places like cruise ships, restaurants, schools, child care centers and swimming pools. It spreads when people do not wash their hands well enough after using the bathroom. They touch a surface such as a door handle or food, and the virus then sticks to the next person who touches that spot and then touches their mouth. Symptoms begin one to two days after exposure and last three to eight days.

Parents should make sure sick children rest, drink extra fluids, and eat or drink foods with salt, according to the American Academy of Pediatrics. They should avoid apple juice, which can cause diarrhea. Antidiarrheal medicine may help older children, but give it only if suggested by your pediatrician.

Parents also should:

  • Wash hands often with soap and warm water. Hand sanitizers will not kill the germs.

  • Clean up vomit and diarrhea immediately with solution of 5-25 tablespoons of bleach per gallon of water. Bleach is the most effective way to kill the virus.

  • Wash linens, bed sheets and other contaminated laundry on the longest, hottest washer setting possible. Dry on high heat. Avoid shaking the laundry before washing. This can spread the virus to other surfaces.

  • Do not prepare food for or share food with others if you are sick.

Infected people can spread the virus to others for days or even weeks after feeling better. Continue to wash hands well with warm, soapy water, especially after using the bathroom.

© 2014 American Academy of Pediatrics. This Parent Plus may be freely copied and distributed with proper attribution.