NSW Health is urging the South Korean community to take care and watch for symptoms of hepatitis A following the diagnosis of eight cases in Sydney and the ACT since June.
Cases were confirmed in areas including the South Eastern Sydney Local Health District, which covers St George and Sutherland hospitals.
Dr Vicky Sheppeard, Director Communicable Diseases NSW Health, says NSW Health is also working closely with the NSW Food Authority to determine whether the cases are linked to a food source.
"Hepatitis A is caused by a virus that spreads in contaminated food or through poor hygiene," she said.
"Symptoms may include nausea, vomiting, fever and yellowing of the skin, dark urine and pale stools.
"Symptoms may be very mild, especially in young children, but anyone with symptoms should see their doctor right away and not handle food for other people."
Dr Sheppeard says Australia has a very low incidence of hepatitis A.
"Despite this, hepatitis A can easily spread from person to person, which is a real risk among the South Korean community in Sydney at present, so we are urging people to take particular care with hygiene," she said.
"This includes washing hands thoroughly in soap and water for at least 15 seconds and drying them thoroughly."
South Korea, where hepatitis A is usually uncommon, is experiencing a large outbreak of hepatitis A with over 11,000 cases reported so far this year.
Two doses of vaccine prevents infection, and at least one dose is strongly recommended prior to travel to countries where hepatitis A poses a risk. The hepatitis A vaccine is available at GPs.