SYDNEY, March 4 (Xinhua) -- Authorities in the Australian state of New South Wales (NSW) have issued a measles health alert for western Sydney as the number of confirmed cases continues to rise toward the total figure for 2025.

The NSW Department of Health said in a warning released on Tuesday night that it is advising people in western Sydney to be alert for signs and symptoms of measles after being notified of a confirmed case who had no known exposure to the highly contagious airborne disease.

"With the source of the infection unknown, it is likely measles is currently circulating within the community, and other people may have been unknowingly exposed to measles," the department said.

The new confirmed case visited several locations across western Sydney while they were unknowingly infectious at the end of February, including multiple medical facilities.

Anyone who attended an exposure site at the same time as the confirmed case has been told to monitor for symptoms, including fever, runny nose, sore eyes and a blotchy red rash, for 18 days.

The warning was the fourth measles alert issued for Sydney since Feb. 21. The Department of Health said there have been 23 confirmed cases in NSW since the start of 2026.

According to the Australian Center for Disease Control's National Notifiable Disease Surveillance System, NSW recorded 37 measles cases for the entirety of 2025. ■