People are being urged to be vigilant if they suspect they could have measles after a new case was confirmed in Auckland late last week.
Auckland Regional Public Health Service (ARPHS) said it believed the person may have caught measles while on a recent trip to Melbourne, where several other cases were also confirmed.
Earlier this month, ARPHS reported the end of an outbreak which saw 24 people diagnosed with measles since mid-January.
But outbreaks of measles were likely to re-appear again, as it was still present in other parts of New Zealand and the world.
Measles must be taken very seriously, said medical officer of health Brad Novak.
"This disease spreads easily through the air, especially from coughing and sneezing and it is highly infectious. It commonly causes ear infections and pneumonia and may lead to other serious complications. It can in some cases also be fatal.
"Our clinical team of public health doctors and nurses is contacting a large number of people who may have come into contact with the person while they were infectious, but before measles was diagnosed, " Dr Novak said.
Prompt identification can help limit the spread of measles to others.
Common symptoms are a red rash that starts on the face and moves to the rest of the body, runny nose, cough, sore eyes or fever.
Anyone with these symptoms should seek immediate medical help.
People are advised to phone ahead before visiting a doctor to minimise the spread of infection to others in the waiting room.
It is also important that anyone who suspects they may have measles, or they have had contact with someone suspected to have measles and are not immune, should remain in isolation to limit the spread of the disease.
People born before 1969 or who have received two doses of the measles, mumps and rubella vaccine (MMR) or who have had measles in the past are considered to be immune.
Immunisation is the only effective way to protect against the disease, says Mr Novak.
Anyone who is not up to date with immunisations should contact their GP or practice nurse and arrange to catch up as soon as possible.
MMR is given in two doses, normally at 15 months and four years of age giving over 95 percent protection.