A measles patient in Milford Sound has probably passed the disease on to at least one other person.
The Milford Sound case was announced on November 20, and authorities have since tried to track everyone that patient — a 30-year-old woman — may have come into contact with.
The woman was the first measles case in New Zealand since May.
Yesterday, a second South Island measles case — in Marlborough — was confirmed, with health officials saying that diagnosis was likely linked to the Milford Sound case.
A third potential case — a man described as a close contact of the pair — has been isolated in Te Anau.
People with measles are infectious for about 10 days.
Southern DHB Medical Officer of Health Susan Jack said the Marlborough patient was a woman in her 20s.
"She has been in isolation in Marlborough since Tuesday, November 20 . . . we are reasonably confident that she would not have passed the virus on to anyone else in that time."
None of the three patients were thought to have been vaccinated against measles. Public health agencies across all South Island DHBs were on the alert for measles cases, Dr Jack said.
In October 2017, the World Health Organisation (WHO) declared New Zealand had achieved endemic measles elimination status, meaning at least 95% of people were fully vaccinated against the disease.
However, a WHO report released this week said there had been a 30% spike in measles cases in 2017 due to holes in vaccination coverage.The few cases of measles since have mostly been imported from overseas.
Measles can be life threatening, and about one in 10 people with measles will need hospital treatment.
