Health officials expect a measles outbreak in Christchurch to spread to other places within the next fortnight.
There are now 44 cases of measles in the city, 26 of which have been officially confirmed. Most are pre-school and school-aged children.
Medical officer of health Dr Cheryl Brunton says infected children will have travelled during the school holidays and it's likely cases will start appearing in those places soon.
Dr Brunton says while the disease is merely unpleasant for most people, it can cause serious complications. Measles is highly contagious.