Auckland DHB was repeatedly warned of "out of control" syphilis rates before it made cuts to sexual health positions, documents show.

Syphilis, once almost eradicated in New Zealand, is at epidemic levels and there have been stillbirths after the sexually transmitted infection was passed on during pregnancy.

The deaths have put a renewed spotlight on funding for sexual health services nationwide, particularly in Auckland, where an overhaul last year saw the number of full time specialist positions covering the entire region drop by 1.65 to 2.1.

Documents obtained by the Herald show last year's overhaul followed strong opposition.

Dr Jason Myers, executive director of the NZ Aids Foundation, wrote to the ADHB in November 2016, saying the proposed changes "only adds to a growing and alarming perception that there is gross lack of political and DHB leadership in responding to the serious HIV and broader sexual health challenges we are facing".

New HIV infections are concentrated in Auckland, Myers noted, and an "exploding and growing" syphilis epidemic among men who have sex with men.

The University of Auckland's gay men's sexual health research group told the DHB of similar concerns, noting a syphilis epidemic "surging out of control" with a roughly 500 per cent rise in cases since 2013.

The Association of Salaried Medical Specialists, representing the senior doctors working for the sexual health service, labelled the changes "nothing more than a cost-cutting exercise", and one that would gut the service's ability to try respond to the syphilis outbreak.

Syphilis is increasingly common in the heterosexual community, including women. It is easily treated with antibiotics, but if not detected during antenatal care can pass on to unborn children, causing stillbirth or serious complications including blindness.

Since the Herald revealed New Zealand has now seen fatal congenital syphilis cases, two former directors of Auckland sexual health service have made contact to express dismay at the changes to the service.

Dr Rick Franklin worked at ADHB for 28 years, including 10 years as clinical director of Auckland sexual health services, and the same length of time as a clinical leader.

He left last year and now works in Australia. DHB employees were often worried about speaking to media about issues, Franklin said, "but I don't give a toss - I'm in Sydney".

Specialists in the service tried everything to convince management they were making an enormous mistake in moving to a nurse-led service, he said.

"The only thing they really seemed to care about was how it might reflect on them, and to keep it all quiet...they are all complicit in this. It is just appalling."

Dr Janet Say, the former director of Auckland Sexual Health Services and who held that position from 1984 to 1995, said the spread of syphilis and death of infants was horrifying, and should never have happened in a country the size of New Zealand.

She objected to the "discriminatory" triage system for clinic bookings introduced along with the staffing changes last year, and said the number of doctor clinic sessions was too low.

ADHB chief medical officer Dr Margaret Wilsher said addressing syphilis rates is a major focus, including through a recent campaign run with the NZ Aids Foundation and Body Positive. That showed early promise - data for quarter two this year showed a 24 per cent drop in infectious syphilis cases among men.

"While it is too early to draw cause and effect conclusions, the drop in cases is encouraging."

A pilot begun in June last year was now permanent, and involves - with consent - encouraging the previous partners of people with syphilis to get tested.

On the changes made to the service last year, Wilsher said they were done after extensive analysis and consultation, and feedback from the NZ Aids Foundation and ASMS was taken very seriously.

Overall staffing positions increased and the level of care "was not adversely impacted by these changes".

"In June this year we refreshed our sexual health clinical governance group. This group of clinicians actively looks at how sexual health is provided right across the sector in the Auckland region, and how this can continue to improve."

There are only eight fulltime sexual health specialist positions across New Zealand, with some DHBs not employing any specialists. That includes in areas where unborn babies have died from syphilis.

The Royal Australasian College of Physicians has criticised the Ministry of Health over its response to the syphilis epidemic, which linked rates to the funding of HIV pre-exposure medication (Prep). That was despite that regime coming into force in March this year and syphilis cases steadily rising since 2013, the college noted.