Norovirus Prevention

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Causing 19 to 21 million cases of acute gastroenteritis each year, norovirus is the most common cause of foodborne illness in the United States, and we’re right in the middle of its peak season.

Often referred to as the stomach flu, norovirus is not caused by influenza but by a different viral strain. So it’s important to understand that the flu vaccine will not protect you against norovirus. There is not yet a vaccine for norovirus. The only protection is prevention.

Being one of the most highly contagious viruses, norovirus spreads when a person accidentally ingests particles of vomit or poop from an infected person or from contaminated food or water. Each infected individual is able to shed billions of particles with every episode of sickness, but it only takes a few dozen particles to make an individual sick.

How norovirus spreads

  • Rooms and surfaces that have experienced episodes of sickness from an infected individual are not cleaned properly
  • An infected person does not wash his/her hands thoroughly after using the restroom or being sick or cleaning up someone else’s sickness and infects others by contaminating surfaces or preparing food for others and transferring particles of vomit or poop onto food through bare hand contact
  • Food is placed on counters that have vomit or poop particles
  • Septic tank leaks into a well
  • Infected person vomits or poops into water
  • Food is grown or harvested with contaminated water
  • Water isn’t treated properly
  • Vomit or poop particles are sprayed through the air and land on food or surfaces that touch food

So consider this, the next time a person publicly vomits (or poops) at school, a store, a restaurant, a community pool get away and go wash your hands thoroughly. Do not eat and do not touch your face until you’ve completely cleansed yourself.

Norovirus symptoms
How do you know if you get norovirus? Most symptoms develop within 12 to 24 hours of exposure and include:

  • diarrhea,
  • vomiting,
  • nausea, and
  • stomach pain.

Other, less common symptoms include: fever, headache, and body aches.

Illness duration and contagion
The illness usually lasts only 1 to 3 days. But infected individuals can still shed contaminated particles for up to two weeks even after all symptoms have subsided.

While norovirus is the most common foodborne illness in the United States, it is typically not the most deadly. It can, however, be an extremely serious illness for the very young or the frail elderly because the biggest danger with norovirus is dehydration. Signs of dehydration include:

  • decreased urination,
  • dry mouth and throat, and
  • feeling dizzy when standing up.

Children may not produce tears when crying and be unusually fussy or sleepy.

Prevention against norovirus infection
As mentioned before, there is no vaccine for norovirus nor is any immunity developed in persons once they become ill. This means people can get norovirus over and over again. The best defense from norovirus is prevention:

  • Wash hands thoroughly with soap and water
  • Always wash hands after using the toilet or changing diapers and before eating or preparing/handling food or giving yourself or someone else medicine
  • Apply an alcohol-based hand sanitizer AFTER washing hands but never as a substitute for washing hands
  • Cook foods thoroughly especially shellfish. Norovirus can be heat resistant and withstand temperatures as high as 145F
  • Keep infected folks away from food prep areas
  • Routinely clean and sanitize kitchen utensils, counters and surfaces before preparing food

How to prevent norovirus transmission if someone in your household is sick
Cleaning is an important part of preventing the spread of norovirus. Remember, this is a highly contagious illness. Controlling cross-contamination opportunities is key to keeping yourself and others norovirus free.

Here’s how to clean:

  • Do it immediately after a person has been sick
  • Protect yourself: wear gloves
  • Clean the entire area with paper towels then disinfect using a bleach-based household cleaner
  • Note that all cleaners are not the same. The product should be a disinfectant (kills germs) rather than a sanitizer (reduces number of germs) and it gets bonus points if it says it specifically is effective against norovirus. Restaurant supply stores are great sources for disinfectant wipes and cleaners
  • To make your own bleach-based disinfectant: combine 5 to 25 tablespoons of household bleach per gallon of water
  • When applying, do not wipe the bleach-based product away. Make sure it stays on the surface for at least 5 minutes then clean the entire area again with soap and hot water.
  • Clean soiled laundry using the hottest water setting and maximum available cycle length then machine dry at the highest heat setting
  • After cleaning anything that has been contaminated with norovirus germs, wash your hands with warm water and soap for 20 seconds and dry hands completely afterwards.

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