OzFoodNet: enhancing foodborne disease surveillance across Australia: quarterly report, 1 October to 31 December 2003.

A key feature of the quarter was the significant number of outbreaks of gastroenteritis spread by person-to-person transmission, especially in outbreaks of norovirus. There were also a large number of outbreaks of foodborne illness prior to Christmas 2003. Also important have been the significant efforts to investigate outbreaks relating to oysters imported from Japan. These oyster related outbreaks highlight the importance of norovirus as a cause of foodborne gastroenteritis with potential for international spread.