An international team of public health scientists have published an analysis of molecular data revealing that the global increase in norovirus infections recorded in late 2012 may be due to a new norovirus variant called Sydney 2012.
Increased levels of norovirus activity in late 2012 were reported in the UK, the Netherlands, Japan, Australia, France and New Zealand. By sharing molecular data from those countries through the NoroNet network virologists have been able to show that a new variant of genotype II.4, first identified in Australia and thus termed Sydney 2012, seems to be associated with the increases. The same variant has also been isolated in the USA.
The authors of the report warn that their findings may mean an unusually high incidence of norovirus infections this season and suggest that healthcare institutions should take appropriate precautions. The report is published in the journal Eurosurveillance and can be found here.