Norovirus Infection causes and Risk Factors

Norovirus is highly contagious and once infections start to occur they are difficult to contain. Knowing the causes and risk factors associated with the virus can help you decrease your chances of contracting this infection. Norovirus accounts for approximately approximately 50% of gastroenteritis cases in the US. One of the reasons this virus is so easily transmitted is due to its resistance to disinfectants.


Common symptoms in people who are infected with the Norovirus are vomiting and diarrhea. If airborne particles manage to contaminate food or drink and the items are ingested, this will likely cause an infection. People who contract the virus tend to be contagious in the 24 to 48 hours before they show symptoms and during the 24 to 48 hours when they are symptomatic.

Unfortunately, the possibility of infection does not stop just because the symptoms have stopped. The virus may continue to spread long after your symptoms cease. Norovirus may be active for weeks in the infected person’s stool.  To further complicate matters, the virus is known to survive in the environment for as long as two to four weeks. This relatively long incubation period allows the virus to spread quickly, especially when people are in close quarters.

Risk Factors 

Being aware of Norovirus risk factors can help you decrease your chances of contracting the infection. One risk factor involves being with a crowd of people who are contained to a relatively small area. Recent Norovirus outbreaks have included hospitals, nursing homes, and cruise ships. If you are in these types of situations being more diligent about things such as hand washing may help to prevent you from contracting the virus.

Other risk factors include having a depressed immune system (for example people living with AIDS) and/or ingesting food or drink that has been improperly handled. In addition, being in an area that has not been routinely cleaned may allow the virus to linger long enough to be transmitted to you. Infants, young children, and the elderly may be especially susceptible to becoming infected. Lastly, using an item that an infected person has used, without cleaning it properly, may lead to an infection. These items would include things like dishes, glasses, and silverware.

While Norovirus infection is common, contracting the virus does not help strengthen your immunity against it. Constant vigilance and an awareness of causes and risk factors associated with the infection are important to helping you to avoid a Norovirus infection in the future.