The disease, also known as pertussis, often started with cold symptoms and can give people a bad cough that can make it difficult to breathe and often finishes with a whooping sound, dry-retching or vomit.
It is particularly dangerous for babies and young children.
New Zealand College of Midwives chief executive Alison Eddy says the latest case was a concern.
“We’ve probably some undetected cases out there, the concerning thing at the moment is that vaccination rates are not as high as they would be ideal so that does put those that are vulnerable to whooping cough - which is particularly very young children - at risk.”
Eddy said more can be done to increase vaccination rates.
Expanding the vaccination workforce would help reduce barriers for those most at risk, she said.
Midwives were qualified to prescribe and administer vaccines, Eddy said, but they were not currently resourced to do so.
The college was calling for the development and establishment of a dedicated pregancy vaccination strategy as well as an awareness campaign.
The college recommends pregnant people get vaccinated from 16 weeks of pregnancy and up to two weeks before birth.
Vaccinations for babies start at age six weeks, and boosters were required a few weeks later.
A top level taskforce has made 54 recommendations to try to turn around the country’s “dire” and unfair childhood immunisation rates.
Among its recommendations was that more vaccinators were trained and employed and improving rates among pregnant people.
- RNZ