A MEASLES warning has been issued in Perth after a person was diagnosed with the illness.

The West Australian Health Department says the person visited several public areas in Perth and Northbridge between July 12 and 14, including Universal Store, Tony Roma’s, Mechanics’ Institute Bar and Polly Coffee Bar.

People should remain vigilant for the onset of measles symptoms for the next three weeks if they are not immune to the infection and visited those places during that period.

Senior Medical Advisor in Communicable Diseases, Dr Clare Huppatz said measles was a serious and highly contagious viral illness that was spread by tiny droplets released when an infected person coughed or sneezed.

“Every measles case is treated as a public health emergency because of the risk of local spread – including to those most vulnerable to infection, such as infants too young to be vaccinated, those with compromised immune systems and pregnant women who are not already immune through vaccination or previous infection,” Dr Huppatz said.

“With high vaccination coverage, naturally occurring measles has been eliminated from WA for around 20 years but occasional cases and small outbreaks still occur – associated with tourists or WA residents who are infected overseas.”

Dr Huppatz said public health staff had been providing information to people who were potentially exposed to the most recent case where they were known but that it was not possible to identify and specifically warn people who were in public places.

“Measles virus survives less than two hours in the air or on objects and surfaces and is inactivated rapidly in the presence of sunlight or heat. It is generally considered safe for non-immune individuals to enter a room 30 minutes after a measles case has left the area,” she said.

People with measles typically develop symptoms approximately 10 days after being exposed to the virus but this can vary from 7 to 18 days. Early symptoms include fever, cough, runny nose and sore eyes, followed by a red blotchy rash three or four days later. The rash usually starts on the face and spreads to the rest of the body.

“It is important for unwell people to call ahead of travelling to a clinic or Emergency Department so that they can be isolated, preventing them from infecting other patients and staff when they arrive.”

Measles is contagious for about four days before and after the development of the rash. Children and adults who have been unwittingly exposed are at risk of developing measles if they are not immune.