A Queensland paramedic seriously ill with measles attended four Brisbane hospitals last week not knowing he was contagious.

The 32-year-old man was also on Moreton Island from May 14 until late on Monday.

He has since been admitted to hospital in a serious condition.

While he was working on May 11 and 12, the man visited Princess Alexandra Hospital, Greenslopes Private Hospital, Lady Cilento Children's Hospital and QEII Hospital on multiple occasions.

The state's chief health officer, Dr Jeannette Young, said they were calling on anyone who might have been exposed to consult their GP and if necessary receive a vaccination.

"Measles is a very, very serious disease and unfortunately this poor gentleman who has contracted measles is actually now in hospital very, very unwell," she said.

"We know one in three people, one in three adults who gets measles does end up in hospital.

"Every single time we need to go out and contact trace anyone who's come into contact with that person during their infectious period.

"We've been having large numbers of measles outbreaks in Queensland for the last couple of years.

Hospitals visited by the infected paramedic: Princess Alexandra Hospital from 7:45pm to 9:30pm and 11:15pm to 12:15am on May 11/12; and 5:45am to 8:10am on May 12

Princess Alexandra Hospital from 7:45pm to 9:30pm and 11:15pm to 12:15am on May 11/12; and 5:45am to 8:10am on May 12 Greenslopes Private Hospital from 12:15am to 1:30am on May 12

Greenslopes Private Hospital from 12:15am to 1:30am on May 12 Lady Cilento Children's Hospital from 9:30pm to 10:30pm on May 11

Lady Cilento Children's Hospital from 9:30pm to 10:30pm on May 11 QEII Hospital from 4:00am to 5:15am on May 12 Source: Queensland Health

"The major message I want to get out today is that we have a very, very effective vaccine available for measles. You need two doses of it to totally protect you."

Metro South health unit director Dr Brad McCall said they were firstly concerned for anyone who had travelled to Moreton Island since May 14.

He said such people should be thinking about their measles vaccination record and if necessary contacting their GPs.

"The second group we're focusing on are people prior to that date who've been in contact with this person," Dr McCall said.

"Those people have been traced already to a number of hospitals in south-east Queensland.

"We'll be working with those hospitals ... to identify people who may have been in that vicinity.

"We'll be checking their status and alerting them to the symptoms of measles and what to look out for."

Dr Young said Queensland Ambulance would also contact their staff who might have come into contact with the paramedic on the job.