Measles alert for Vic plane passengers

An unvaccinated toddler with measles may have passed the highly contagious disease on to passengers on a flight from Indonesia to Melbourne, authorities say.

Passengers on a flight from Jakarta to Melbourne are being warned to watch for measles symptoms. (AAP)

Passengers on a flight from Jakarta to Melbourne are being warned to watch for measles symptoms after a toddler contracted the highly contagious disease and may have had it on the plane.

Victoria's acting chief health officer says the three-year-old boy was admitted to hospital on the weekend after flying into Melbourne on Garuda Indonesia flight GA 716 on May 13.

"Anyone developing symptoms is advised to ring ahead to their GP or hospital first and tell them that they have fever and a rash," Brett Sutton said in a statement on Monday.

"If you know you have been in contact with a measles case, please alert your GP or hospital emergency department."

The disease usually initially presents as common cold symptoms that develop into a rash three to seven days later.

The health department says people aged 26 to 42 have the lowest immunisation coverage to the disease but those of any age who are immunocompromised are also at higher risk.

This includes people undergoing cancer treatment or on high-dose steroids.

Most cases of measles in Victoria are linked to international travel.