Controlling Norovirus

You may hear norovirus called “the stomach flu.” Some viral illnesses that cause vomiting and diarrhea are caused by norovirus. You can become infected with norovirus many times in your life.


  • Is very contagious. Norovirus can spread quickly in places like daycare centers, nursing homes, schools, restaurants and cruise ships.
  • Causes diarrhea and vomiting, often at the same time. Some people also have nausea, stomach cramps and a fever.
  • Symptoms usually start within 12 to 48 hours after exposure, and usually go away within one to three days.
  • Is most contagious when people are sick and during the first few days after they recover. However, the virus can stay in your stool for two weeks or more after you feel better.

Report Suspected Outbreaks of Norovirus

Report to the Health Department an increase in illness above the expected or “normal” rate.

Steps to Control an Outbreak of Norovirus in Schools or Childcare

Hand Washing

  • Remind students, staff and volunteers to carefully wash their hands with soap and water, especially after using the restroom and always before eating or preparing food.

Stay Home if You are Sick

  • Children, staff and volunteers who are sick with symptoms of norovirus should stay home from school or daycare until 24 hours after symptoms have stopped.
  • Food workers should be restricted from preparing or handling food until 48 hours after symptoms have stopped.

Clean Soiled Areas Safely

  • To prevent exposure to the virus, wear disposable gloves, masks, eye protection and protective clothing when cleaning up soiled areas. When done cleaning, remove these items in a way that prevents contaminated surfaces from touching the skin. Dispose of these items in a sealed garbage bag.

Remove Vomit or Stool

To reduce further exposure to others, promptly clear of all non-essential students and staff the area where the illness occurred. Immediately clean and disinfect contaminated surfaces.

  • Use paper towels (or another disposable absorbent material) to clean visible debris. Double bag and discard.
  • For carpeted areas, use an absorbent material (like kitty litter or dry oatmeal) to absorb liquid. Double bag and discard.
  • To minimize particles in the air, don’t use a vacuum to clean vomit or stool.


Norovirus can stay on surfaces for several days or weeks. After cleaning the surface, immediately disinfect it with a chlorine bleach solution. Apply diluted household chlorine bleach to hard, non-porous, surfaces. Leave the disinfectant on the surface for 10 minutes, rinse with water, then air dry.

  • Mix a concentration 5000 ppm (1 ½ cup per gallon) for surfaces that have been visibly contaminated.
  • Mix a concentration 1000ppm (1T household bleach per quart) to disinfect non-soiled surfaces.
  • Alternately, other disinfectant registered as effective against norovirus by the Environmental Protection Agency (EPA) may be used. Refer to the list of EPA approved disinfectant. Be sure to follow the manufacturer’s recommendations. Quaternary Ammonium (Quat) based sanitizers that are often found in schools are not effective against noroviruses.
  • Increase the frequency of cleaning and disinfecting within the building.
  • Clean and disinfect bathrooms, and frequently touched objects such as faucets, handles, doorknobs, handrails and desks several times each day until the outbreak is over.
  • Carpets should be steam cleaned at 160°F for five minutes.
  • Clothes or linens that become contaminated with vomit or stool should be handled carefully. Wear gloves while handing soiled items and wash your hands after removing gloves. Wash soiled items with detergent then machine dry on high heat setting.
  • Never mix bleach with ammonia or other chemicals.

Food Service

  • Stop buffet, family style or self-service menus (like sharing common food at each table or salad bars).
  • If a self-service menu is unavoidable, all food should be individually packaged or wrapped (i.e. serving salads in clamshell boxes).
  • Serve food directly to each student from the kitchen staff or service line during lunch.
  • Halt PTSA food sales, potluck, and sharing of foods brought from student’s or staff homes.