Decriminalising sex work could slash the world’s HIV infections by a third or more, according to a new study.

Published yesterday in health journal The Lancet, the paper says that punitive treatment of sex workers can “elevate HIV acquisition and transmission risks”.

In Cambodia, which has Southeast Asia’s highest rate of HIV prevalence, sex work is a central driver of the epidemic.

“[C]riminalisation and stigma deter access to condoms or health services [and] continue to hamper HIV prevention, treatment, and care efforts,” the study says, adding that more outreach is not enough.

“Decriminalisation of sex work would have the greatest effect on the course of HIV epidemics across all settings.”

Worldwide, sex workers are disproportionately affected by HIV. Earlier this month, the World Health Organization found that female sex workers were 14 times as likely as other women to be infected.

While the Kingdom has successfully reduced the rate of HIV-positive adults from 2 per cent in 1998 to under 0.7 per cent, the rate for sex workers hovers nearer 14 per cent, according to the National AIDS Authority.

“On average, there are three new infections each day,” NAA deputy director Tia Phalla said. “Legalisation is not the problem, the problem is . . . reaching the high-risk populations.”

But rights groups argue – and the study agrees – that infections among high-risk groups like sex workers would be a lot easier to find and treat if the trade weren’t driven underground by the law.

Since 2008, more than 3,000 sex workers have been arrested and detained by police, according to Keo Tha of the Women’s Network for Unity. In several instances, carrying condoms led to the arrest, and condoms have been used as evidence.

“The owner[s] of massage parlours and beer gardens are too scared to stock condoms now because they’re afraid police will use it against them,” said Mey Sovannara, communications officer at the Khmer HIV/AIDs NGO Alliance. “The only option we have to speed up the battle against the infection is to legalise, not marginalise.”

ADDITIONAL REPORTING BY KHOUTH SOPHAK CHAKRYA