Headlines

A new norovirus variant—GII4 (Sydney 2012)—responsible for the majority of clustered cases of acute gastroenteritis reported to the National Reference Center for Enteric Viruses: Since the beginning of week 44 (October 29, 2012), samples have been received at the National Reference Center for Enteric Viruses – Dijon University Hospital for 175 of the 183 (96%) gastroenteritis outbreaks reported to the NRC, the vast majority of which originated in nursing homes. A norovirus was identified in 102 of the 114 (89%) outbreaks for which definitive virological results are available at the NRC. The emergence of a new GII4 genotype variant for this season has been reported by the National Reference Center for Enteric Viruses, and this virus is implicated in more than three-quarters of the 102 clusters of norovirus-associated gastroenteritis cases. This new variant, Sydney 2012, was recently published in Eurosurveillance. New variants of norovirus GII4 emerge every 2 to 3 years and may be associated with larger-scale outbreaks.