Health officials warn a confirmed case of measles has been identified in Brisbane.

A measles alert has been issued after an unknowingly infectious man flew from China to Brisbane on Saturday.

Measles is one of the most infectious of all communicable diseases and is spread by tiny droplets generated through coughing and sneezing.

Passengers who arrived in Brisbane on China Southern Airlines flight CZ 381 from Guangzhou on the morning of January 5 are urged to be alert for signs of the highly infectious disease.

The man also visited the Prince Charles Hospital Emergency Department from noon to about 10.30pm on Saturday.