What is Norovirus?

Norovirus is an example of a highly contagious, small, non-enveloped virus transmitted through food, water and touching contaminated surfaces. In the U.S., it is the leading cause of illness and outbreaks from contaminated food. Norovirus can spread quickly in closed places like daycare centers, nursing homes, schools and cruise ships.

A person with norovirus infection can shed billions of norovirus particles but it only takes as few as 18 viral particles to infect another person. During outbreaks, norovirus can spread in several different ways. For example, a person who is infected by eating contaminated food in a restaurant can spread the virus to household members through direct contact or indirectly by touching objects and surfaces.

The pathogenicity of norovirus makes testing and analysis of disinfection performance difficult and challenging. Instead, scientists rely on surrogate bacteriophages such as MS2 and Qβ.