Three South Australian teenagers have tested positive for measles, prompting statewide contact tracing and a pop-up vaccine clinic.

Three cases of measles in SA teenagers have been linked to a fourth case reported last week.

The outbreak takes the total number of measles cases in SA this year to eight. The state had only seven cases in all of 2025.

SA chief public health Officer Professor Nicola Spurrier told ABC Radio on Friday that 93.3 per cent of South Australians were vaccinated against measles, but vaccination rates had fallen each year.

“There are some people who have decided not to vaccinate their kids, and those people need to think, ‘Should I actually be making that decision?’,” she said.

“One case of measles in an unvaccinated community will spread that to approximately 14 other people. They then would spread it to 14 other people. All those people would spread it to 14 other people, each one of them.”

SA Health has published a list of possible exposure sites where the teenagers had been while infectious. They can be found here.

“Even if the person’s left the shopping centre, if they’re in an enclosed area, it’s infectious there for 30 minutes after they’ve left. It is a lot of people, and that’s why we’ve got quite broad times for people to look at,” Spurrier said.

Measles is a highly contagious, airborne infection that can cause severe complications, including pneumonia and encephalitis, an infection and inflammation of the brain.

“It is a day — 24 hours — before you actually get any symptoms, and that’s why it also spreads easily, ’cause you don’t even know that you’ve got it,” Spurrier said.

Symptoms begin with fever, cough, a runny nose and sore eyes, followed by a blotchy rash that usually starts on the head before spreading down the body.

SA Health says anyone who suspects they have measles should phone their doctor before visiting and explain the reason for the appointment, so they can take precautions to prevent the disease from spreading to others.

“The one person that really cares about you, and your health, and your family’s health, is your local GP, or, indeed, your local pharmacist… Make a time and see those people and get the right information,” Spurrier said.

Republished from InDaily