Foods and Water Protocols

Norovirus causes acute gastroenteritis (sometimes called the "stomach flu", though this virus is not related to the flu virus). Symptoms of norovirus gastroenteritis include nausea, vomiting, diarrhea, and abdominal pain. There are an estimated 9.2 million cases of foodborne norovirus infection in the United States each year1. According to the U.S. Centers for Disease Control and Prevention (CDC), food and drinks (including water) can easily become contaminated with norovirus because the virus is very small and because very few (10-100) norovirus particles can make a person sick2. Food and water can become contaminated in numerous ways.

Contain Outbreaks
How Can Food Become Contaminated?
How Can Water Become Contaminated?
Norovirus Infection and Food Handlers


Prevent Outbreaks

  1. Observe strict hand hygiene standards. Always wash and sanitize hands before eating, preparing, or serving food.
  2. People who are sick with symptoms of gastroenteritis should never prepare or serve food, and should be excluded from these activities until at least 48-72 hours after symptoms resolve.
  3. Environmental surfaces, including bathroom surfaces, surfaces frequently touched by hands (door knobs, faucet handles, light switches, remote controls, etc.), and all food preparation surfaces, should be disinfected regularly with products that are registered by the Environmental Protection Agency (EPA) as appropriate for use against noroviruses, such as Clorox® Regular-Bleach1, concentrated*.

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Contain Outbreaks

  • Dispose of any contaminated food/beverage items.
  • Identify and eliminate sources of contamination in the water supply. Fecal contamination from untreated sewage is a common cause of water supply contamination.
  • Sick persons should be prohibited from preparing or serving food for at least 48-72 hours after the last symptoms have cleared; this is because people will continue to shed norovirus in their fecal matter for several days after recovery from norovirus symptoms.
  • Intensify hand washing and sanitization efforts- norovirus contaminated hands can contaminate foods and surfaces and make others sick. CDC recommends the use of an alcohol-based hand sanitizer along with hand washing3.
  • Also remember to disinfect environmental surfaces and objects that may have become contaminated with norovirus with a disinfectant registered with the EPA to kill norovirus.

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How Can Food Become Contaminated?

  • Food can be contaminated by contact with contaminated hands of someone infected with norovirus (whether or not they have symptoms of the virus). Hands become contaminated with virus when they come in contact with vomitus or fecal matter† even microscopic amounts.
  • Food work surfaces can become contaminated with stool or vomitus.
  • Tiny droplets of vomitus that contain virus particles are formed when someone ill with norovirus vomits, and the droplets can travel through the air over short distances and land on food or food preparation surfaces.
  • Foods can be contaminated with norovirus by ill food handlers during preparation before being delivered to a restaurant or store. Prepared foods that are eaten without further cooking or heating (such as sandwiches or salads) pose a particular concern.

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How Can Water Become Contaminated?

  • Potable water supplies can become contaminated when water treatment is compromised and untreated sewage makes its way into drinking water supplies.
  • Several outbreaks have been caused by the consumption of oysters harvested from contaminated waters2.
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Norovirus Infection and Food Handlers
According to the CDC, people working with food who are sick with norovirus gastroenteritis can easily unintentionally contaminate the food he or she is handling. Many of those eating the contaminated food may become ill, causing an outbreak2. CDC estimates that as many as half of all food-related outbreaks of illness may be caused by norovirus. In many of these cases, sick food handlers were thought to be implicated. Always wash and sanitize hands frequently when handling or preparing food.
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*Clorox® Regular-Bleach1, concentrated is registered to kill Norovirus (as Feline Calicivirus)

References

  1. Mead PS, Slutsker L, Dietz V, et al. Food-Related Illness and Death in the United States. EID 1999; 5: 608-625.
  2. Norovirus: Food Handlers, Centers for Disease Control and Prevention, http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus-foodhandlers.htm
  3. Norovirus in Healthcare Facilities Fact Sheet, 2006 http://www.cdc.gov/ncidod/dhqp/id_norovirusFS.html