Public health officials are urging Cantabrians to get vaccinated following the confirmation of a third measles case.
An 18-year-old woman is the third person in a fortnight to be diagnosed with the virus.
The virus spreads easily from person to person through the air via breathing, coughing and sneezing.
Health officials say the woman visited Christchurch Hospital's emergency department over the weekend.
Patients and visitors who were in the waiting room at the time are being urged to get vaccinated immediately.