Stomach Flu: Norovirus Symptoms, Transmission and Prevention

'Tis the season for Norovirus infection, more commonly known as the winter vomiting bug. Although called "stomach flu" it is no relation to influenza. What can you do to protect yourself from this rampant infection?

What Is Norovirus?

Noroviruses, also known as Norwalk-like viruses (NLV), are a group of nonenveloped RNA viruses that cause acute gastroenteritis or stomach flu. Considered highly contagious, as few as 10 viral particles are sufficient to infect an individual. Although cases can be seen throughout the year, outbreaks are more common in winter months when people spend more time indoors, in close proximity.

Symptoms of Norovirus

Symptoms usually appear within 12 - 48 hours of infection, typically last one to three days and may include:* nausea
* vomiting and/or diarrhea
* fever
* headache
* abdominal cramping
* fatigue

Is Norovirus Dangerous?

Although norovirus can make a person feel awful, the infection is self-limiting and typically not life threatening. Since the infectious agent is viral, there is no medication used specifically to treat the infections, on to reduce symptoms. Antibiotics, which are used to fight bacterial infection, do not help in the treatment of strictly viral infections.

Those who are sick may vomit and have bouts of diarrhea several times throughout the day. The main danger is dehydration that can occur if an individual is not able to drink enough liquids to replace the fluids lost through vomiting and diarrhea.

How Is Norovirus Transmitted

Norovirus can be found in the stool and vomitus of an infected person, and may be shed for up to three weeks after symptoms are gone. A person can become infected when the virus enters the mouth of a person who has:* touched surfaces or objects contaminated with virus and then brought hand to mouth
* consumed foods or drinks contaminated with virus
* had direct contact with vomit or stool of ill person when caring for them
* drunk from same cup or used the same utensils as an ill person
* had immediate contact with aerosol of a vomiting person

How to Prevent Infection

The following measures can reduce your chances of becoming infected with norovirus:* Wash your hands frequently and thoroughly, especially after using the toilet and changing diapers and before handling food.

* Carry hand sanitizer with your for use after you've touch surfaces in public places (i.e. shopping cart handles, bathroom door handles, etc.

* Wash fruits and vegetables, as any uncooked food could contain viral particles.

* If someone has been sick in your home, clean and disinfect all surfaces, toys, doorknobs, handles, etc. by using a bleach-based cleaner.

* Wash clothing or linens that may be contaminated using hot water and soap.

* If you believe that you are infected with norovirus, do not prepare food while you have symptoms and for at least 3 days after your symptoms resolve.

More Information on Infectious Disease

To learn more about how to protect yourself from infectious disease, see the Virtual Microbiology Classroom or the CDC Norovirus Page.

Sources

Bauman, R. (2004) Microbiology. Pearson Benjamin Cummings.

Talero, K. P (2008) Foundations in Microbiology Basic Principles. McGraw Hill Companies.

Photo: Purchased from iStock # 000009904783.jpg.

Please note: The information in this article is not to be followed as medical advice, diagnosis or treatment. Please consult with your physician or primary health practitioner for information regarding your own personal health and necessary treatments.

* Article originally published in Suite101 online magazine.