Sunday, October 16, 2011

HIV Study Renews Scrutiny of Hormonal Contraception

    In the media world, the most precious real estate is page one, above the fold of The New York Times, which on 4 October featured this headline: “Contraceptive Said to Double Risks of H.I.V.: Study’s Findings Pose Quandary in Africa.” In the fi rst quote in the story, a foreign policy expert said, in essence, that if the new findings about injectable hormonal contraceptives used by many African women were true, “we have a major health crisis on our hands.”
     The Times story posed a quandary for some HIV/AIDS researchers who study female contraceptives and HIV risks, a research niche that has a long history of conflicting reports. For many poor women in sub-Saharan Africa, HIV and pregnancy are “competing risks,” as having a child presents both health and socioeconomic downsides. Evaluating the contribution that injectable hormones make to HIV transmission is also fraught with confounding variables that complicate analyses of cause and effect.
      Although the Times attempted to put the new findings in context and noted that they had limitations, some researchers worry that the global infl uence of the newspaper’s account will overshadow the many complexities in the data that leave open critical questions about whether injected contraceptives truly pose an HIV risk.
     Epidemiologists Maria Wawer and Ronald Gray, a husband-and-wife team at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, for the most part applaud the study featured by the Times. “They’re a good group, and it’s a good study,” says Wawer, who with Gray has evaluated injectable hormonal contraceptives and HIV risks in Uganda. But their own study is one of many that found no increased risk from these contraceptives in women they followed for 5 years. They further note that the Times story did not point out that the new study had very small numbers of infected women, analytic issues, and possibly misleading information because of selfreporting by participants about frequency of sex and condom use. “I’m afraid this is going to set family planning in Africa back a decade,” says Wawer, who worries that African media and health ministers will discuss the Times report more than the new data.
      The study followed 3790 couples in seven African countries in which one partner at the outset had a known infection with both HIV and herpes simplex virus-2 (HSV-2). Led by a team from the University of Washington (UW), Seattle, the study aimed to assess whether treating HSV-2 with acyclovir could thwart HIV transmission—it did not—and couples used whatever contraception they chose. As the authors note in the paper published online by The Lancet Infectious Diseases on 4 October, the contraceptive use was “observational”: It was not a defi nitive trial of women randomly assigned to different contraceptives. The researchers note that self-reporting could also bias results: Women using hormonal contraceptives, for example, may have used condoms less often than claimed and thus had more exposure to HIV.
      Roughly two-thirds of the HIV-infected partners at the study’s outset were men, and of the 1314 uninfected women, about 15% used an injectable contraceptive (mainly Depo-Provera) at some point during the 6-year study. Only 10 of the women using injectable hormones became infected, which did not reach statistical significance until researchers adjusted the data for variables including age, HIV concentration in infected partners, and pregnancy, which itself increases the risk of infection. (Oral contraceptive use was extremely low and did not lead to significant results.) In the adjusted analysis, the women who used the injectable hormones had twice the risk of becoming infected than those who did not, with an annual incidence of infection of 6.85% versus 3.78%. A separate, adjusted analysis of uninfected men found that having sex with an HIV-infected woman who used the injectable hormones at least doubled the risk of transmission. “It was really hard news for me to hear, and it’s really hard to report,” says the study’s leader, UW Seattle epidemiologist Jared Baeten. “That said, wishing it away doesn’t help the situation.”
     Charles Morrison, an epidemiologist at FHI360 (formerly Family Health International) in Durham, North Carolina, co-authored a commentary that said the rise of HIV transmission and hormonal contraception remains “an unanswered question.” The commentary notes that five of 12 published studies—all in women at high risk for infection—have linked hormonal contraception to transmission. So did a persuasive experiment in monkeys published in Nature Medicine 15 years ago. He characterizes the new study as a “decent secondary analysis” and says it “does add to our suspicion level, but it’s by no means conclusive.”
      Morrison’s own large study—which documented 76 infections in women who used injectable hormones—found an increased risk only when his team did a fine-grained analysis and discovered higher transmission
in younger and HSV-2 negative women. “This is a tough area,” he says. “Sexual behavior, contraception, pregnancy, and HIV transmission are all correlated, and it becomes quite hard to tease them all apart.”
    Baeten and his team well recognize the pregnancy risks. “I wouldn’t want our results to be interpreted as an excuse to diminish contraceptive use in the world,” he says. “They should reinforce something that may not be pushed as hard as it should be: Counsel women that surely hormonal contraception doesn’t decrease risk and may increase it and should be used along with condoms.”
      In response to the new fi ndings, the World Health Organization has convened a “technical consultation” to begin 31 January 2012 with experts to “re-examine the totality of the evidence” to see whether it needs to revise recommendations about hormonal contraceptive use in women.



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