A measles expert is warning students to check their vaccination status after a confirmed measles case at the University of Otago

Health officials are racing to find how the 18-year-old woman got the disease.

Immunisation Advisory Centre director Dr Nikki Turner says the main challenge is stopping the spread.

She says measles is one of the most highly infectious diseases known.

Turner says it can be caught as easily as when two people are standing across the room from one another.