Norovirus (Stomach Flu)
What is Norovirus?
Norovirus is a group of viruses that cause acute gastroenteritis, often called the stomach flu or winter vomiting disease. This is not influenza or the flu, which is a respiratory infection caused by the influenza virus.
Norovirus outbreaks occur in B.C. communities every year. Outbreaks of illness are common in nursing homes, daycare centres, schools, children's camps and on cruise ships.
What are the symptoms?
Within a day or two of being exposed to a norovirus you may have an upset stomach and start vomiting, often followed by cramping, chills, fever and diarrhea. The illness usually begins suddenly and lasts only for 1 to 3 days. Complications may occur if people lose too much fluid from vomiting and diarrhea and do not drink enough fluids. This is more likely to occur with babies, the elderly and people with weakened immune systems. Severe illness is very rare and hospital care is usually not required.
How does the virus spread?
Norovirus can be found in the vomit and diarrhea of people who are sick. When someone vomits, people nearby may become infected by swallowing tiny droplets from the air.
The virus can also be spread on surfaces like countertops. The virus can survive for a long time on surfaces such as countertops or sink taps if not properly cleaned.
People can become ill when they touch these surfaces and then place their hands or fingers in their mouth. The virus can be spread among people if they do not wash their hands or if someone with this illness handles food, water or ice.
Is there a treatment?
Currently, medications are not usually used to treat norovirus. People infected with norovirus usually get better within a few days.
Antibiotics should not be taken for norovirus. Antibiotics only work to fight bacteria and not viruses.
It is important that you drink enough clear fluids, such as water, so you do not get dehydrated. You should also drink other fluids such as juices, clear soups, or oral rehydration fluids for vomiting or diarrhea.
See a doctor if diarrhea or vomiting lasts more than 2 or 3 days, or if dehydration is a concern. If 3 or more people are ill at the same time, report this to your local public health unit.
How can the virus be prevented?
- There is no vaccine or medication that can prevent norovirus infection.
- The key to preventing the virus or reducing it from spreading is hand washing, especially after using the toilet, changing diapers or before eating or preparing food. Proper hand washing requires warm running water, soap and cleansing of the hands for about 30 seconds. For more information see HealthLink BC File #85 Hand Washing for Parents and Children.
- Bathrooms used by sick people should be disinfected with a dilute bleach solution (1 part household bleach to 9 parts water).
- Any food that has been handled by a person with the virus or exposed while a person vomited should be thrown out.
- Dishes and utensils should be washed with hot water and detergent or in a dishwasher.
- Laundry soiled with vomit or diarrhea should also be washed with hot water and detergent.
- People who are ill and work as food handlers or care providers should stay away from work while they are sick and for 2 days after they are better. Even when diarrhea and vomiting have stopped, the virus can still be in the stool (bowel movement) for as long as 2 weeks. Be sure to wash hands carefully and often.
- If someone is ill with norovirus, discourage visitors to the home. It is best to wait for a couple of days after everyone is better and the house is cleaned and disinfected.
- When a family member is sick with vomiting or diarrhea, it is a good idea for that person to try to stay in a separate room and not be around others. Everyone in the family should wash their hands often with soap and water. Use different towels or paper towels for drying hands to help stop the spread to other people.
How can I reduce the risk of getting infected from cleaning up vomit or diarrhea?
If you are cleaning up vomit or diarrhea, you can reduce the risk of getting infected by doing the following:
- Wear disposable gloves. Reusable rubber gloves may be used, but they should be washed after use.
- Use paper towels to soak up excess liquid and put the paper towels and any solid matter directly into a plastic garbage bag.
- Clean the soiled area with soap and hot water. The same cleaning cloth or sponge should not be used to clean other areas of the house as this may spread the virus.
- Disinfect the area that has been washed with a freshly made bleach solution. Make a solution of bleach by mixing 1 part of bleach to 9 parts of water. Household cleaners other than bleach do not work for most of the viruses that cause vomiting and diarrhea.
- Put all cleaning cloths and disposable gloves into a plastic garbage bag.
- Wash your hands well using soap and warm water for at least 30 seconds.