OzFoodNet: enhancing foodborne disease surveillance across Australia: quarterly report, January to March 2004.

Salmonella incidence increased during the quarter and was responsible for 46 per cent of foodborne outbreaks. Large numbers of norovirus outbreaks continued to be reported in aged care facilities and hospitals. Several outbreaks were related to eggs, although traceback efforts were unsuccessful. A third outbreak of norovirus implicating a different brand of oysters imported from Japan was significant, resulting in action to remove the oysters from the marketplace. These outbreaks have resulted in reconsideration of the safety of oysters harvested from contaminated waters in other countries.