Recreational and drinking waters as a source of norovirus gastroenteritis outbreaks: a review and update

The distribution of noroviruses is worldwide. In industrialized countries, noroviruses are the most common viral cause of gastroenteritis outbreaks and play an important role in sporadic gastroenteritis as well. Transmission may occur through the ingestion of contaminated foods or water, through person-to-person contact, or by way of direct contact with contaminated surfaces. Of particular importance is their ability to cause waterborne outbreaks linked either to the direct consumption of water or to its recreational uses. This article reviews the clinical manifestations and epidemiology of norovirus infection, and describes over 40 waterborne norovirus outbreaks, their respective probable sources of contamination and - where water samples were tested - the genetic types identified.