What are noroviruses?
Noroviruses are a group of viruses that cause the “stomach flu,” or gastroenteritis (GAS-tro-enter-I-tis), in people. The term norovirus was recently approved as the official name for this group of viruses. Several other names have been used for noroviruses, including:
- Norwalk-like viruses (NLVs)
- caliciviruses (because they belong to the virus family Caliciviridae)
- small round structured viruses
Viruses are very different from bacteria and parasites, some of which can cause illnesses similar to norovirus infection. Viruses are much smaller, are not affected by treatment with antibiotics, and cannot grow outside of a person’s body.
What are the symptoms of illness caused by noroviruses?
The symptoms of norovirus illness usually include nausea, vomiting, diarrhea, and some stomach cramping. Sometimes people additionally have a low-grade fever, chills, headache, muscle aches, and a general sense of tiredness. The illness often begins suddenly, and the infected person may feel very sick. The illness is usually brief, with symptoms lasting only about 1 or 2 days.
What is the name of the illness caused by noroviruses?
Illness caused by norovirus infection has several names, including:
- stomach flu – this “stomach flu” is not related to the flu (or influenza), which is a
- respiratory illness caused by influenza virus.
- viral gastroenteritis – the most common name for illness caused by norovirus
gastroenteritis refers to an inflammation of the stomach and intestines. - acute gastroenteritis
- non-bacterial gastroenteritis
- food poisoning (although there are other causes of food poisoning)
- calicivirus infection
How serious is norovirus disease?
Norovirus disease is usually not serious, although people may feel very sick and vomit many times a day. Most people get better within 1 or 2 days, and they have no long-term health effects related to their illness. However, sometimes people are unable to drink enough liquids to replace the liquids they lost because of vomiting and diarrhea. These persons can become dehydrated and may need special medical attention. This problem with dehydration is usually only seen among the very young, the elderly, and persons with weakened immune systems. There is no evidence to suggest that an infected person can become a long-term carrier of norovirus.
How do people become infected with noroviruses?
Noroviruses are found in the stool or vomit of infected people. People can become infected with the virus in several ways, including:
- eating food drinking liquids that are contaminated with norovirus
- touching surfaces or objects contaminated with norovirus, and then placing their hand in their mouth
- having direct contact with another person who is infected and showing symptoms (for example, when caring for someone with illness, or sharing foods or eating utensils with someone who is ill).
Persons working in day-care centers or nursing homes should pay special attention to children or residents who have norovirus illness. This virus is very contagious and can spread rapidly throughout such environments.
When do symptoms appear?
Symptoms of norovirus illness usually begin about 24 to 48 hours after ingestion of the virus, but they can appear as early as 12 hours after exposure.
Are noroviruses contagious?
Noroviruses are very contagious and can spread easily from person to person. Both stool and vomit are infectious. Particular care should be taken with young children in diapers who may have diarrhea.
How long are people contagious?
People infected with norovirus are contagious from the moment they begin feeling ill to at least 3 days after recovery. Some people may be contagious for as long as 2 weeks after recovery. Therefore, it is particularly important for people to use good handwashing and other hygienic practices after they have recently recovered from norovirus illness.
Who gets norovirus infection?
Anyone can become infected with these viruses. There are many different strains of norovirus, which makes it difficult for a person’s body to develop long-lasting immunity. Therefore, norovirus illness can recur throughout a person’s lifetime. In addition, because of differences in genetic factors, some people are more likely to become infected and develop more severe illness than others.
What treatment is available for people with norovirus infection?
Currently, there is no antiviral medication that works against norovirus and there is no vaccine to prevent infection. Norovirus infection cannot be treated with antibiotics. This is because antibiotics work to fight bacteria and not viruses.
What can I do to prevent norovirus gastroenteritis?
- Wash your hands frequently with soap and water, especially after using the restroom, handling food, or touching common surfaces. Hand sanitizers are not as effective against norovirus, so thorough handwashing is key.
- Disinfect frequently touched surfaces such as doorknobs, light switches, keyboards, and shared equipment. Regular cleaning can significantly reduce the risk of transmission.
If you are sick or know you have norovirus:
- Stay home if you’re feeling ill. If you have symptoms of norovirus, please stay home and avoid coming to work to prevent spreading the virus. Employees should remain symptom-free for at least 48 hours before returning to work.
- Avoid preparing food for others if you are sick. Norovirus can spread through contaminated food, so it’s essential that any food preparation is handled by healthy individuals during this time.
For more information visit the Centers for Disease Control: https://www.cdc.gov/norovirus/index.html
All outbreaks are immediately reportable to the Camden County Health Department
For norovirus prevention and outbreak guidelines visit: https://www.nj.gov/health/cd/topics/norovirus.shtml
