WA Health is urging anyone planning on travelling overseas to ensure they are fully protected against measles.
It comes after three new cases were identified in returned travellers from Bali, taking the total number to 13 since July 2025.
Four of those cases were returned overseas travellers and nine have been locally acquired.
Further exposure locations have been identified in the local community.
These include at the Mandurah Visitor Centre, Mandurah Forum, Kwinana Marketplace, Ampol Foodary Baldivis and The Knock Restaurant in Rockingham.
Measles is highly infectious and can spread via airborne droplets to people close by (e.g. in waiting rooms).
Droplets in the air may still infect people entering a room up to 30 minutes after an infected person has left it.
Measles typically develops around 10 days after being exposed to the virus, but this can vary from 7 to 18 days.
If someone not already immune to measles visited an exposure location during the specified dates and times, they are advised to monitor for symptoms between 7 to 18 days after the visit.
Persons who have received two measles vaccinations and those born before 1966 are considered immune to measles, on rare occasions, vaccinated individuals may develop a mild illness.
Community invited to name crane towers building new Mandurah Hospital
Hundreds of volunteers remove 525kgs of rubbish from Mandurah's waterways
Port Kennedy man fined $4.2k for failing to feed horse
Rockingham General Hospital patients face the longest waits for elective surgery
Australian-first drone technology to monitor emergencies, crimes in Baldivis, Kwinana, Rockingham
Teen accused of ordering firebomb attack on Baldivis tobacco shop
City of Mandurah sees sharp rise in animal cruelty reports
Geoff Valentine returns to Peel Thunder as senior coach
Golden Bay woman charged with lacing colleague's curry lunch with snail poison