Two of the biggest problems facing women in parts of Africa are complications from unwanted pregnancies, and HIV. So if a new study is correct, and a commonly used contraceptive hormone injection doubles your risk of spreading HIV, then it's going to be a public health nightmare.

Top image via Associated Press.

A new study by University of Washington researchers, published in The Lancet, looked at heterosexual couples in seven African countries where one partner had HIV and the other partner didn't. And the study found that HIV-negative women using injectable hormone contraception were almost twice as likely to contract HIV from their partners (6.61 percent, versus 3.78 percent.) Meanwhile, HIV-positive women who used hormone injections had a 2.6 percent rate of transmission to their HIV-negative male partners, versus 1.5 percent for women who didn't use the injectable hormones.


You can read the full text of the study here — it's free, but registration is required.

So what's going on here? It's possible that part of this increased risk is because the men were less likely to use condoms when their partners were taking contraception, but the researchers corrected for condom use.

Also, the researchers also found that endocervical concentrations of HIV-1 RNA were more likely to show up in HIV-positive women who were using hormonal contraception. And the women using hormonal contraception also tended to have higher concentrations, on the whole. In other words, the HIV virus appeared to have an easier time replicating in the women who were using hormone shots. And this was just localized to the genital region — there wasn't a higher concentration of HIV in these women's blood, just in their genital fluid.


As the study notes:

Clinical and laboratory studies have suggested possible mechanisms by which hormonal contraception could influence HIV-1 susceptibility and infectiousness including changes to vaginal structure, cytokine regulation, CCR5 expression, and cervicovaginal HIV-1 shedding.

But the Times quotes one of the study's authors, epidemiologist Renee Heffron, as saying the research on whether hormonal contraception causes changes to genital tissue or vaginal mucous has been inconclusive. It's also possible that the hormone causes "immunologic changes in the vagina and cervix" that make it easier for HIV to replicate, according to Charles Morrison with FHI 360, a nonprofit that studies the relationship between family planning and HIV.


Few of the women in the study were using oral contraception, so the study's results seem to apply mostly to injectable contraception, which is a much higher dose, all at once.

As the New York Times article notes, injectable contraception is a popular method in many parts of Africa, as Isobel Coleman, with the Council on Foreign Relations tells the Times:

You don't need a doctor, it's long-lasting, it enables women to control timing and spacing of birth without a lot of fuss and travel... If it is now proven that these contraceptions are helping spread the AIDS epidemic, we have a major health crisis on our hands.


As another doctor tells the Times, this is a relatively inexpensive form of contraception that the woman doesn't need to remember to take every day, and it's safe for community health workers to deliver.

Already, an epidemiologist with the World Health Organization tells the Times that the W.H.O. is "going to be reevaluating W.H.O.'s clinical recommendations on contraceptive use."

And yet, the estimated 12 million women who use injectable contraceptives in Sub-Saharan Africa don't have an immediate alternative. Already, the Times notes, hundreds of thousands of women suffer from "injuries, bleeding, infections and even death in childbirth from unintended pregnancies." There's also the fact that pregnancy, too, can increase the risk of HIV transmission.


The bottom line, for now, is that this research isn't conclusive — there'll have to be other studies before we can know for sure if there's a definite link between injectable contraception and HIV. But if these findings can be concerned, then Sub-Saharan Africa's reproductive health nightmare could be getting even more heart-breaking. [The Lancet, via New York Times]