What You Should Know About Norovirus

Norovirus is in the news again this winter, and it is causing illness on continents around the globe. Recent outbreaks of this virus have been reported in England, Wales, New Zealand, Japan and Canada. In the US outbreaks have been reported in states across the country including Massachusetts, Oregon, California, and Florida. In January, 83 people were sickened with norovirus at a resort hotel in Palm Beach County Florida, and at a veteran's home in Chula Vista California 73 residents became ill. Outbreaks in two Boston hospitals impacted more than 70 patients and staff.

What is it about this virus that allows it to infect so many people and cause so much wide spread illness? Norovirus has a set of tools in its microbial toolbox that is quite impressive. Here are some of the factors that make norovirus such a difficult pathogen to control:

  • Norovirus causes excessive environmental contamination because of the sudden onset of uncontrollable diarrhea and projectile vomiting. The virus propels itself in every direction landing on objects, surfaces, hands, or food.
  • The virus then survives in the environment for days to weeks- it is resistant to heat, cold, UV radiation, detergents, and even some disinfectants.
  • A very small amount of norovirus is all that's needed to cause infection- this is called the 'infectious dose'- and only 10 to 100 viral particles are needed to cause infection.
  • You can get norovirus again and again- strains are continuously changing and immunity to any one strain is thought to be short lived (lasting only a few months).

When you take into consideration all of these aspects, it is easier to understand why noroviruses cause so much illness. Though once you understand how the virus works, it's easier to protect yourself and your loved ones. It starts with simple hygiene. Frequent hand washing and disinfecting the environment are easy enough to do yet critical things you can do to help fight off norovirus.