Foodborne disease investigation across Australia: annual report of the OzFoodNet network, 2003.

In 2003, OzFoodNet conducted enhanced surveillance of foodborne diseases across Australia, which covered all states and territories. During 2003, there were 23,250 notifications of eight potentially foodborne diseases, of which 67 per cent and 30 per cent were due to Campylobacter and Salmonella infections respectively. The most common Salmonella serotype was Typhimurium, as in previous years. Most S. Enteritidis were acquired overseas, except for Queensland where 52 per cent of infections were acquired locally. Locally acquired S. Enteritidis infections in Australia were predominantly due to phage type 26. The most common serotype of Shiga toxin producing E. coli was O157, although for 49 per cent of notified infections serotype was unknown due to the use of polymerase chain reaction based screening tests. There were 12 materno-foetal listeriosis infections in 2003, which was an increase compared to recent years. During 2003, there were 444 outbreaks of gastroenteritis and foodborne disease recorded. Ninety-nine of these were of foodborne origin affecting 1,686 persons, hospitalising 105 and causing six deaths. A wide range of agents and foods caused these outbreaks, with Salmonella Typhimurium being the most common pathogen. Outbreaks associated with fish and seafood dishes, poultry meat, and Asian style and imported foods were common. Four outbreaks with international implications were reported: an outbreak of Salmonella in Montevideo involving contaminated tahini from the Middle East and three outbreaks of norovirus infection associated with imported Japanese oysters. Outbreak data indicated a need to monitor food safety in aged care settings, restaurants and catering. Eighty-nine investigations into clusters of gastrointestinal illness where a source could not be identified were conducted, including multi-state outbreaks of salmonellosis. One multistate investigation of antibiotic resistant Salmonella Paratyphi b Java identified 18 cases who had recent exposure to tropical fish aquariums. Ninety-seven per cent of Salmonella notifications on state and territory surveillance databases have complete information on serotype and phage type. In 2003, OzFoodNet demonstrated the benefits of national collaboration to control food borne disease.