Recently published research suggests that use of hormonal contraceptives, particularly injectables, may double the risk of HIV (see K4Health blog, October 7, 2011). On October 20, 2011, a global teleconference took place to give advocates, researchers, and policy makers an opportunity to discuss this research and its implications.
Sponsored by AVAC (Global Advocacy for HIV Prevention), the teleconference included study investigators Dr. Jared Baeten and Renee Heffron of the University of Washington in Seattle, Washington, USA, and Dr. Helen Rees of the University of Witwatersrand in Johannesburg, South Africa. Also on the teleconference were Dr. Mary Lyn Gaffield, Scientist at the World Health Organization (WHO), and Dr. Charles Morrison, Senior Epidemiologist at FHI 360.
Baeten emphasized that “this kind of international discussion is important…to put the findings into perspective.” After a brief recap of the findings, originally published in The Lancet Infectious Diseases
, the speakers answered several critical questions that have been raising concern in the international public health community.
Do the study findings pertain to hormonal contraceptives in general, or to injectables or oral contraceptives specifically?
Although the primary analysis of the study was among women using any hormonal contraceptive method compared with women not using a hormonal method, Baeten explained that the data came largely from injectable users. “Most interpretations of the study have focused on HIV risk associated with injectable use. I think that’s the best interpretation,” stated Baeten. Because there were few study participants who used oral contraceptive pills, the study could not make a reliable estimate of HIV risk among pill users. Baeten speculates that the study findings are probably most relevant to the DMPA injectable because it was the most common injectable used in the countries where the study was conducted.
How do the recent findings compare with findings from previous research on DMPA use and HIV risk?
Putting the new study findings into historical perspective, Charles Morrison explained that 5 of 14 prospective studies have found a statistically significant risk of HIV with use of DMPA injectables. However, more of the studies showed no increased risk with DMPA use. Furthermore, the studies that did find an increased risk of HIV tended to be among populations at high risk of HIV, such as sex workers—but this was not always the case. In summary, Morrison maintained that the evidence to date has been mixed, which, he argues, points to the need to design a more definitive randomized controlled study.
What about pregnancy itself being a risk factor for HIV?
Helen Rees summarized findings from a parallel study
that found that pregnant women who were infected with HIV were two times more likely to transmit the infection to their uninfected male partners than non-pregnant women with HIV. While Morrison pointed out that the body of evidence on pregnancy and HIV risk also show mixed results, Rees expressed:
What this means programmatically is that, if we accept the data, you’ve got a bit of a problem because on the one hand it would appear from this data that DMPA increases the risk of HIV acquisition. On the other hand, if women stop using these methods and get pregnant then their risk of HIV acquisition is also increased…you’ve got quite a dilemma for HIV if you accept these data.