Investigating an outbreak of staphylococcal food poisoning among travellers across two Australian States

Abstract

Introduction:

Staphylococcus aureus is a common cause of staphylococcal food poisoning in Australia, with several outbreaks associated with foods prepared by commercial caterers. Laboratory testing on cases of gastrointestinal illness caused by enterotoxin producing S. aureus is not routinely done as this condition is self-limiting. Hence outbreaks of such illness may go undetected.

Methods:

A retrospective cohort study was conducted amongst a group of tourists who were hospitalized in Sydney shortly after flying from Queensland. The group had consumed food prepared by a restaurant on the Gold Coast prior to transit. Laboratory analysis on stool specimen was conducted in Sydney. An environmental assessment of the restaurant in the Gold Coast was conducted and environmental specimens assessed for contamination.

Results:

Epidemiological investigations linked the outbreak to a restaurant in the Gold Coast where the suspected food was produced. Stool samples from two of the hospitalised cases were confirmed to have enterotoxin producing S. aureus and several environmental samples were found to be contaminated with S. aureus as well. Investigations suggested that absence of hand washing and other unhygienic food handling at the implicated restaurant was the likely cause of this outbreak.

Conclusion:

Food poisoning due to toxin mediated S. aureus is frequently undetected and under reported. Public health units should consider toxin producing pathogens such as S. aureus when investigating outbreaks where vomiting is the predominant symptom and occurs rapidly after consuming food.