Syphilis still a pressing problem: expert

Work needs to be stepped up to develop a vaccine for syphilis which has lost its "bogeyman" status, says an Australian expert.

The disease still kills half-a-million babies worldwide annually, a situation described by Professor Basil Donovan as "an international scandal".

In Australia, urban gay men and young Aboriginal heterosexuals in remote communities were the two population groups affected, the Professor of Sexual Health at the University of NSW told AAP.

He co-wrote Syphilis: a fresh look at an old foe in the Sexual Health journal's special issue on the disease.

They say syphilis remains a pressing public health problem globally across different populations, including men who have sex with men and pregnant women.

"How is it that an infection that is curable with a single shot of penicillin, and after 70 years shows no signs of penicillin resistance, is resurgent worldwide?," they ask.

While penicillin cures an infection, a person can go on to catch it again as no vaccine has been developed.

"It doesn't seem to be an issue because the treatment is so cheap and easy, therefore it doesn't scare people any more," Prof Donovan told AAP.

In its peak, and for centuries, it killed more people and in more miserable ways than HIV did at its peak in 1994, he said.

"But as soon as there was a cure the bogeyman disappeared."

There seemed to be "precious little interest" in developing a vaccine which would mainly be used in poor countries where there was not much money to be made, he said.

Many people don't get any symptoms so they can have it for years and unknowingly infect other people.

It can cause brain injury and it's likely it will affect babies of infected pregnant women.

At the very least, the more sexually active gay men and expectant mothers should have optimal access to testing and treatment, the authors said.