(Acute Nonbacterial Gastroenteritis; Caliciviruses; Food Infection; Norwalk Virus; Norwalk-like Virus; Small Round Structure Viruses [SMRVs]; Stomach Flu; Viral Gastroenteritis)
by Cynthia M. Johnson, MA
Norovirus infection happens in the stomach and intestines. It spreads quickly to others.
A group of viruses cause this infection. They can spread through:
The viruses can also spread by being around someone who is sick.
Any person who ingests the virus is at risk of getting this infection. It is more common in young children and older adults.
This infection is common in crowded settings such as:
Problems may be:
These signs often appear within 24 to 48 hours of getting the virus. They often last about 2 to 3 days.
The doctor will ask about your symptoms and health history. A physical exam will be done. This is often enough to make the diagnosis.
Stool tests may be done if the doctor wants to find out which virus is causing the infection.
Viral infections cannot be treated with antibiotics. The infection will go away on its own. Symptoms can be managed with:
To lower the risk of this problem:
Centers for Disease Control and Prevention
National Institute of Allergies and Infectious Diseases
Public Health Agency of Canada
Bok K, Green KY. Norovirus gastroenteritis in immunocompromised patients. N Engl J Med. 2012 Nov 29;367(22):2126-2132.
Norovirus. Centers for Disease Control and Prevention website. Available at:
...(Click grey area to select URL)
Accessed October 30, 2020.
Norovirus infection. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/norovirus-infection. Accessed October 30, 2020.
Last reviewed September 2020 by EBSCO Medical Review Board James P. Cornell, MD
Last Updated: 5/4/2021