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Cambodia’s Doomed PREP Trial: What Happened Next?

Guest blog by Gavin Yamey, lead, Evidence to Policy Initiative, Global Health Group, University of California San Francisco

Remember the doomed PREP (pre-exposure prophylaxis) trial, examining whether tenofovir protects female sex workers (FSWs) from HIV, which was shut down by Cambodia’s Prime Minister in the face of pressure from activist groups?  The serious public health implications of the trial’s termination were discussed in a 2004 PLoS Medicine essay:

“Speculation, unwarranted criticism, overreaction, or sensationalizing facts risk stigmatizing tenofovir and could jeopardize future attempts to find an efficacious PREP. This is in nobody’s interest.”

Last week, one of the Principal Investigators of that trial, Kimberly Page, gave a fascinating lecture at the University of California San Francisco, in which she told the audience how she turned the crisis of the trial’s shutdown into an opportunity.

The trial was literally shuttered overnight, said Dr Page, an epidemiologist who studies sexually transmitted infections (STIs).  Fortunately, she said, “the NIH,” which funded the trial, “let me keep the money.”

A new research partnership was formed, which included community partners.  Out of the ashes of the terminated PREP trial was born a new project, the Young Women’s Health Study (YWHS), which examines HIV risk factors among Cambodia’s FSWs.

YWHS is a prospective cohort study of young FSWs (15-29 years) working in a variety of settings in Phnom Penh, Cambodia.  The results are helping to inform outreach services and prevention campaigns to promote the health of FSWs.

In 2001, Cambodia launched a “100% condom” program, modeled on Thailand’s program of the same name, aimed at achieving 100% use of condoms during commercial sex work.    One problem with this campaign, explained Dr Page, is that it was targeted at brothel-based FSWs in Cambodia—it missed the “informal” FSWs, such as those who were freelancers, or worked in massage parlors or karaoke lounges or as beer promoters.  Most FSWs, said Dr Page, do not work in brothels.

The YWHS, which recruited 200 women in the first phase of the study, found an HIV prevalence of 23% at baseline.  Risk factors for being infected were being a freelancer, younger age at first sex, and recent use of any amphetamine-type stimulant, such as “yama” (a pill form of amphetamine).  Reaching freelancers (who work in parks and streets) with prevention services is therefore an important public health challenge.

A second phase of the study includes qualitative research to examine FSWs’ use of yama.  Dr Page shared some of the results of this research.  Women described yama as a “power drug,” she said—FSWs say that yama gives them energy, so they can work longer hours and generate more income.  It also makes them disinhibited and they say it makes them less likely to use condoms.

In February 2008, Cambodia passed a new law to tackle trafficking, outlawed prostitution, and forced brothels to close.  “On one day,” said Dr Page, “we were told ‘there are no more sex workers, they don’t exist.’” The governmental agency responsible for HIV surveillance was no longer able to conduct surveillance on FSWs.  Since brothels were closed down, brothel-based FSWs simply moved to the streets and became freelancers, facing an increased risk of violence, or shifted to working in entertainment establishments.  Community groups working with FSWs, said Dr Kimberly, found that it became harder to reach women.  “There has also been increased stigma, with a fall in women seeking STI services.”

“Many advocacy groups,” she said, “say the new law has actually increased the exploitation of women.”  In a January 2011 news feature in The Phnom Penh Post, discussing the YWHS and the new anti-trafficking law, Chris Jones, the Cambodia country manager for the NGO Population Services International, says:

“The shift of sex work from brothels to entertainment establishments has greatly complicated HIV prevention efforts, which rely on regular, unfettered access to women at risk of HIV to deliver information, products and referral to services such as STI and HIV testing and access to family planning services.”

Dr Page and colleagues, in their report on the first phase of YWHS, concluded that their study findings coincide with major policy changes in Cambodia that highlight the need for urgent attention to vulnerable young women in Cambodia.

“The recent intensification of anti-trafficking efforts,” they write, “could result in further increases in risk exposure and reduced access to prevention. Within this context, there is an urgent need for both effective behavioral and biomedical interventions and an enabling environment committed to their implementation, so as to reduce the effect of the HIV epidemic on this highly vulnerable population.”

Gavin Yamey leads the Evidence-to-Policy initiative (E2Pi) in the Global Health Group at the University of California San Francisco.Gavin Yamey was formerly a Senior Editor at PLoS Medicine.

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