New strains of norovirus and the mystery of viral gastroenteritis epidemics

摘要

Norovirus was first identified in 1972 as the cause of a gastroenteritis outbreak in Nor-walk, Ohio, and it became famous because of severe outbreaks on cruise ships in 2002. Norovirus is the cause of 50%-70% of gastroenteritis outbreaks and at least 5 global gastroenteritis epidemics since 1996. A biennial pattern of alternating quiescent and epidemic outbreak activity associated with the emergence of new norovirus variants has been identified in Alberta and some European countries.A new strain called GII.4 Sydney was first reported in Australia in March 2012 and has become the predominant strain worldwide. The GII.4 Sydney strain was first detected in Alberta, Canada, in September 2011, Denmark in January 2012, and the United States in September 2012. GII.4 Sydney has been the predominant strain worldwide since November 2012.