A measles epidemic could hit Hawke's Bay after a child from outside the region visited public places in Napier with the highly-contagious disease, including the National Aquarium on June 9 between 10am and noon.
Measles can be life threatening - about 1 in 10 people contracting the disease need hospital treatment.
It can lead to complications including: permanent hearing loss, diarrhoea, pneumonia, seizures and in rare cases swelling of the brain causing permanent brain damage or death.
Hawke's Bay District Health Board's medical officer of health, Rachel Eyre, said measles was a very infectious disease and anyone not immune was at risk if they have come into contact with a person who has the disease.
It spreads via minute breath droplets from breathing, coughing and sneezing and is contagious from before symptoms begin until about five days after onset of a symptomatic rash.
The illness starts 10 to 14 days after contact with the virus, with symptoms including fever, runny nose, cough, and sore eyes.
After three to five days a rash appears on the head and spreads down the body.
Dr Eyre said there was currently an epidemic of measles in several parts of New Zealand.
"In Hawke's Bay we have high rates of immunisation coverage with the MMR vaccine (Measles, Mumps, Rubella), but we can't be too complacent about the likelihood of measles spreading in our community," she said.
"Now is a good time to check your immune status. You are immune if you have received two MMR vaccinations, were born before 1969 or if you have previously had measles.
"Immunisation is the best way for us all to protect ourselves against measles and is free to those who need it. You can protect both yourself and the community by getting immunised."
Anyone who thinks they might have measles should stay away from work, school or public places.
If you think you might have measles you should contact your GP by phone or Healthline on 0800 611 116 for more advice.