Queensland Health is grappling with a measles outbreak in a prison north of Brisbane.
Queensland Health says four prisoners at the Woodford Correctional Centre, near the Sunshine Coast, have tested positive to the highly-contagious disease.
Another is also highly likely to have contracted the disease.
There are concerns there will be many more measles cases at the jail due to the highly condensed population inside the facility.
Authorities will investigate any links between the prison cases and others in Brisbane and across Ipswich.
To mitigate further risks to staff, visitors and prisoners, a mass immunisation campaign will be rolled out at the jail, according to Queensland Health communicable diseases unit acting director Stephen Lambert.
"We are dealing with a highly condensed population of around 150 staff and 900 prisoners who work and live in close proximity," he said.
"This means more cases are highly likely as a large number of staff and prisoners have potentially been exposed."
Authorities urged anyone born in or after 1966 who has visited the Woodford prison since October 21 to check their immunisation status.
The measles infection causes fever, cough and a red spotty rash.
Anyone that has been at the prison and has symptoms should contact a GP immediately, Queensland Health says.
