Otago schools, early childcare centres and tertiary institutions are being warned by the Ministry of Health to be on the lookout for measles.
This follows an outbreak of the highly infectious disease in the North Island.
At least 61 measles cases have been recorded in New Zealand in the past three months.
Of those, 43 were in Auckland, 15 in the Bay of Plenty/Lakes district and three in Wellington.
Public health officials are bracing for more after it was found 20 cases were pupils at Westlake Boys' High School in Auckland.
The outbreak is believed to have originated in the Philippines, arriving in New Zealand via a hip-hop dance competition in Sydney, which was attended by a South Auckland 18-year-old.
Other outbreaks have occurred in recent months in Australia, Europe, the United Kingdom, Africa, Asia, India and North America.
Associate Health Minister Jo Goodhew said frontline health services, including travel clinics and emergency departments, were encouraged early last month to help counter the spread of measles. It is a highly infectious virus that spreads easily from person to person through the air, via breathing, coughing and sneezing. It is four times more infectious than influenza.
The ministry has sent information to education facilities across Otago, warning them to keep an eye out for children with symptoms.
Parents were advised to make sure their children's measles, mumps and rubella (MMR) vaccinations were up to date.
The ministry said the best protection was the MMR vaccine, which was free for all children and adults born after January 1, 1969 who had not received two doses of a measles vaccine.
Affected people must stay away from school and follow the advice of their GPs.
''Anyone who has not been fully immunised or those with no immunity to measles and who have been in close contact with a measles case during the infectious stages must stay away from school for 14 days from their last contact,'' the ministry said.
Kaikorai Valley College principal Rick Geerlof said teachers were being extra-vigilant.
If a child became unwell with possible measles, the pupil would be separated from other children and sent to the office until being picked up.
''This helps minimise the risk of measles spreading,'' Mr Geerlof said.
Mrs Goodhew said anyone who suspected they might have measles should call their GP, or Healthline on 0800 611-116, as soon as possible.
• Illness usually starts 10-12 days after exposure.
• Symptoms include fever, runny nose, sore and watery pink eyes; sometimes small white spots on the back inner cheek of the mouth.
• Rash usually starts 3-7 days into the illness, on the face, behind the ears, over the head, then down the body.
• Rash lasts up to a week.
• Measles infectious from five days before to five days after the onset of rash.