Public health officials have warned people to check their immunisation if they intend visiting Australia where several states are in the grip of a measles epidemic.
Auckland Medical Officer of Health Dr Catherine Jackson said: "If people are heading overseas these holidays it will pay to check you're immune. If you're not immune and you're travelling it's a good idea to get immunised before you go."
A similar warning is being sounded by the Bay of Plenty and Lakes District Medical Officer of Health Dr Neil de Wet, who said anyone under 45 should make sure immunisations were up to date, especially if living in or visiting Taupo or Turangi.
"Contact tracing helps for those most obviously at risk but lots of people might have been exposed and no one would know."
De Wet said so far all the region's confirmed cases were from two extended families and those who were infectious were being isolated at home. But there was no risk to fellow passengers on the dancers' return flight to New Zealand as none were infectious when they travelled.
Authorities were identifying people who might have been in contact with those affected and health professionals and emergency departments were being told to look out for people with possible symptoms.
Jackson said 38 dancers from five Auckland groups and a further 94 people who had been in contact with the woman during her infectious period had been traced since the Auckland Regional Public Health Service was notified. They included staff and patients at a general practitioner's waiting room and a chemist and friends who stayed for a sleepover at her home. Almost everyone she had been with was either immune or vaccinated. "We have just one other case under investigation - we think it's very unlikely - [it] was a brief contact and she's not particularly unwell but until the tests come back we take it very seriously," said Jackson.
More than 80 people had been traced in Taupo and Turangi including 32 family and friends of the seven-strong Original Kids Krew team, and more than 40 who were in medical waiting rooms when infectious patients arrived.
A Waikato District Health Board spokeswoman said none of the 20-strong Hamilton and Huntly contingent was found to be infected.
Jackson said that during a 2011 New Zealand outbreak one child infected more than 500 people. "You can catch the measles by being in a room an infectious person has been in two hours prior."
A health website lists measles alerts for New South Wales, Queensland, South Australia and regions in North America and Europe.
