Controlling Outbreaks of Viral Gastroenteritis In Schools

  • Noroviruses are a frequent cause of outbreaks of gastroenteritis (vomiting and diarrhea).
  • They are almost always transmitted from person to person, and occasionally by contaminated food or drinks.
  • Objects or surfaces contaminated with vomitus or stool may be a source of illness. The contamination may not be obvious.
  • These outbreaks can be controlled by taking specific steps to prevent the virus from being transmitted from person to person.
  • Exclusion from school of those who are ill, hand washing and environmental cleaning are essential for outbreak control.

Management of those who are ill

  1. New gastrointestinal illnesses in students or staff should be reported immediately to the school nurse.
  2. New cases should be recorded using a case log, and submitted daily to CCDPH.
  3. Ill students and staff should be excluded from school until 24 hours after their symptoms have resolved.

Hand Hygiene

  1. Ensure that students, staff and visitors are washing their hands frequently, particularly prior to snacks and meals.
  2. Handwashing posters should be prominently posted in the facility.
  3. Ensure that supplies for hand washing (i.e., soap, disposable towels) are consistently available.
  4. Alcohol-based hand rubs (gel or foam) can be used in situations where it is not possible to use soap and water and should be provided by the facility.

Facility Disinfection

  1. Educate cleaning and maintenance staff of the risk of infection while performing their duties and the need for strict compliance with hand hygiene.
  2. Use freshly prepared bleach solution (household chlorine bleach diluted 1 part to 50 parts water) to disinfect hard, non-porous, environmental surfaces contaminated with stool or vomitus. Leave the bleach solution on the surface for 10 – 20 minutes, then rinse with clean water.
  3. Gloves should be worn during cleaning. Staff must wash their hands with soap and water after the gloves are removed.
  4. Increase the frequency of routine environmental, bathroom and toilet cleaning, using the bleach solution. Particular attention should be given to cleaning objects that are frequently handled such as faucet and door handles, and hand rails. This enhanced cleaning should continue for at least 72 hours after the last documented case.
  5. Consider the use of respiratory protection (surgical mask) for cleaning staff use during cleaning activity.
  6. Noroviruses may remain viable for up to 12 days in carpeting or other environmental surfaces. Clean carpets and soft furnishings with hot water and detergent or steam clean. Dry vacuuming is not recommended because it can re-circulate the viruses.

Food preparation

  1. Food handling staff should be especially careful in handwashing and glove use while the outbreak is ongoing because they may become infected and start shedding the virus before becoming symptomatic.
  2. Food handlers who are symptomatic MUST NOT prepare or serve food for others under any circumstances.
  3. Clean all food preparation surfaces thoroughly with antimicrobial detergent or diluted bleach solution (see above under “facility disinfection”)
  4. Any symptomatic food handlers must be restricted from preparing or serving food until they are symptom free for 72 hours.
  5. Prohibit sharing of communal food/snack items and foods brought from home.
  6. Do not allow use of self-service food bars in the cafeteria. Do not let students/staff serve themselves in any manner that might allow direct contact with shared foods.

Visitors

  1. Notify visitors about the existence of an outbreak and what precautionary measures should be followed.

Laboratory Testing

  1. In an outbreak situation, arrangements can be made to have specimens (stool or vomitus) tested for norovirus at the Illinois Department of Public Health Laboratory.
  2. The Cook County Department of Public Health will determine if testing is necessary.

Contact information
If the number of cases increases, or if you have questions, call the Communicable Disease Control Unit at (708) 492-2150.