Updated: January 12, 2018
A norovirus is a highly contagious infection that contains RNA and is surrounded by a coating of protein. There are at least 25 different strains of norovirus that affect humans.
The spread of the virus can be hard to control as it spreads the infection before symptoms appear. Mostly young children, the elderly, and people who have a weakened immune system are at a higher risk of getting this infection.
In most cases of norovirus infection are mild. But complications can occur and are related to the degree of dehydration. Norovirus infection can cause severe dehydration, malnutrition and even death especially in children and older adults with compromised immune systems.
People who cannot replace the lost fluid by drinking may require hospitalization for intravenous fluids. Pregnant women should pay more attention to keeping up with fluid losses and electrolyte imbalances. Severe dehydration may lead to preterm labor.
Underlying disease may put elderly person especially at risk for complications related to dehydration, including kidney failure. Warning signs of dehydration include:
Children who are dehydrated are unusually sleepy or fussy and cry with few or no tears.
It is necessary to do specific tests to identify the virus as most of the symptoms of norovirus are similar to those of other common viral diarrhea like rotavirus. Norovirus cannot be cultured in a laboratory. However using polymerase chain reaction (PCR) tests, the RNA inside the virus may be detected directly.
Enzyme-based immunoassays (EIA) can also be used to detect the virus in stool samples. EIAs use special antibodies that attach to virus particles. The human body makes antibodies against norovirus which can be identified with immunoassay testing of blood samples. This test is not useful for real-time diagnosis as it takes 10-14 days for the body to make antibodies.
PCR test is the most preferred test as it helps distinguish between other diseases such as rotavirus and Salmonella infections that may produce similar symptoms. It is not necessary to test every person if norovirus has been confirmed in an outbreak setting. Once it is diagnosed, people with typical symptoms are assumed to have acquired the virus.
There is no specific treatment for norovirus infection. The illness usually recovers within a few days and depends on the health of your immune system. It is important to replace lost fluids by drinking lots of fluid to prevent dehydration. You may be given fluids intravenously if you are unable to drink enough fluids. Over-the-counter anti-diarrheal medication is recommended if you are under the age of 65.
Anyone can become infected more than once as it is highly contagious. Good hygiene is the key to preventing a norovirus infection, especially when you stay in a crowded area. The following things should be done to help prevent its spread: