Doctors are urging the government to step up in the fight against sharply rising rates of syphilis - which has taken the lives of two babies.
In a letter to the Associate Health Minister Julie Anne Genter, the Royal Australasian College of Physicians (RACP) said there has now been cases of congenital syphilis, where an infection was passed on from a pregnant woman to her unborn baby.
Earlier this year, the Ministry of Heath said the number of New Zealanders with syphilis has doubled over the last two years.
The symptoms of syphilis depend on the stage of infection, but can include genital ulcers or warty growths, rashes, fever and hair loss.
"The main concern is that we have a disease that was on the way out, which is now coming back. It's a disease we would not expect to be troubled with in New Zealand, in our health system," said Dr Jeff Brown, who penned the letter.
There had been increasing difficulty in accessing sexual health services, particularly in Auckland, where clinics had been cut back, Dr Brown said.
There are only eight full-time sexual health specialists employed across the country, he said.
The RACP is asking the government to establish an electronic surveillance system that correctly tracks cases of the infection, and to resource services appropriately to curb the spread of the disease.
Ms Genter said the previous government hadn't made sexual health a priority, or taken action on the syphilis increase.
She also blamed them for not putting sexual health targets in place - so funding to fight an increase in illness in HIV and syphilis was not made available.
An awareness campaign in Auckland made some improvement to the numbers in the region.
"Even when we were in opposition last year it was clear that syphilis figures were increasing, in fact they've come down slightly in Auckland.
"So I'd say there's already been a bit of a response which has been effective but we need to ramp that up, and the physicians are absolutely right to raise awareness of the issue."
It was obvious there needed to be a huge focus on prevention, testing and treatment, Ms Genter said.
A review of the health system is currently underway.