A 22-year-old woman who helped prepare food at two catered events was diagnosed with hepatitis A in March, meaning that more than 200 people at one corporate event and about 100 at a second event, along with co-workers and roommates, had to be vaccinated.

South Australia Health refused to release any specific details, but did note there was an unrelated but "significant" increase in hepatitis A cases in SA and Victoria in a separate outbreak.

SA Health Communicable Disease Control Branch director Dr Ann Koehler said,

"We think it is probably a vegetable, but we just don’t know yet."