Outbreak of rotavirus worse since 2012

More than 1300 cases have been recorded by NSW Health this year

Health officials are scrambling to find out if a mutant strain of a gastro virus is behind a surge in outbreaks in children and the elderly across NSW.

More than 1300 cases of the highly contagious virus have been recorded by NSW Health this year, with 412 of these recorded last month - the worst outbreak since 2012.