Study: Injectable contraceptive use found to double HIV risk in Africa
According to a study published in The Lancet Infectious Diseases, women in Africa who used the injectable contraceptive depot medroxyprogesterone acetate doubled their risk of becoming HIV-infected and passing the virus on to their male partners.
Women in Africa who used injectable contraceptives doubled their risk of becoming HIV-infected and passing the virus on to their male partners, according to a new study published Monday.
"Among couples in which there was an HIV positive man and an HIV negative woman, if she was using hormonal contraceptive, her risk of getting HIV was doubled," said study author Jared Baeten of the University of Washington in Seattle. "Similarly, in couples where there was an HIV infected woman and an HIV negative man, if the woman was using hormonal contraceptives her chances of passing the virus to her partner were doubled."
Almost 3,800 couples with one HIV-infected partner from the African countries of Botswana, Kenya, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe participated in the study. The majority were in their mid-30s and they were followed for up to two years.The study, published in the Lancet Infectious Diseases, also showed the risk of infection was significantly higher for women who used injectable contraceptives compared with those using birth control pills. Both injectable and oral contraceptives increased the risk for men, but again only the increase in those using the injectable form was statistically significant. In fact, the men were twice as likely to become infected with HIV if their female partners used oral contraceptives compared with couples where women used no birth control at all.
"These findings have important implications for family planing and HIV-1 prevention programs, especially in settings with high HIV-1 prevalence," Baeten said. "HIV risk that could be related to contraception is important from a public health point of view. For individual women using hormonal contraception, it's incredibly important that they be counseled that contraception does not protect them from HIV and indeed it increases their risk and thus using condoms along with contraception is critically important to protect against HIV."
Researchers believe this is the first study to show increased risk in male partners from HIV-infected women using hormone contraceptives. They say more studies are needed for other types of birth control containing hormones such as implants and patches and other methods including intrauterine devices.
"Recommendations regarding contraceptive use, particularly emphasizing the importance of dual protection with condoms and the use of non-hormonal and low-dose hormonal methods for women with or at risk for HIV-1, are urgently needed," said lead author Renee Heffron, University of Washington.
The contraceptive used in the study was depot medroxyprogesterone acetate, one of the most commonly used injectable contraceptives for birth control. DMPA was approved for contraceptive use in the United States in 1992 and contains progestin only. The long-acting contraceptive is injected every three months (four times a year), considered nearly 100% effective and has been used by millions of women across the globe, including several million here in the US, according to the National Library of Medicine.
Some of this study's limitations are that the data used was self-reported and specific brands of contraceptives were not recorded. There also was no data collected on whether the women stuck to the injection schedule. Dr. Charles Morrison, Family Health International 360, says there have been unanswered questions on the issue for more than two decades. He says more studies are needed.
"Active promotion of DMPA in areas with high HIV incidence could be contributing to the HIV epidemic in sub-Saharan Africa, which would be tragic," Morrison said. "Conversely, limiting one of the most highly used effective methods of contraception in sub-Saharan Africa would probably contribute to increased maternal mortality and morbidity and more low birth weight babies and orphans–an equally tragic result. The time to provide a more definitive answer to this critical public health question is now."
The Lancet Infectious Diseases, Early Online Publication, 4 October 2011 doi:10.1016/S1473-3099(11)70247-X
Background Hormonal contraceptives are used widely but their effects on HIV-1 risk are unclear. We aimed to assess the association between hormonal contraceptive use and risk of HIV-1 acquisition by women and HIV-1 transmission from HIV-1-infected women to their male partners.
Methods In this prospective study, we followed up 3790 heterosexual HIV-1-serodiscordant couples participating in two longitudinal studies of HIV-1 incidence in seven African countries. Among injectable and oral hormonal contraceptive users and non-users, we compared rates of HIV-1 acquisition by women and HIV-1 transmission from women to men. The primary outcome measure was HIV-1 seroconversion. We used Cox proportional hazards regression and marginal structural modelling to assess the effect of contraceptive use on HIV-1 risk.
Findings Among 1314 couples in which the HIV-1-seronegative partner was female (median follow-up 18·0 [IQR 12·6—24·2] months), rates of HIV-1 acquisition were 6·61 per 100 person-years in women who used hormonal contraception and 3·78 per 100 person-years in those who did not (adjusted hazard ratio 1·98, 95% CI 1·06—3·68, p=0·03). Among 2476 couples in which the HIV-1-seronegative partner was male (median follow-up 18·7 [IQR 12·8—24·2] months), rates of HIV-1 transmission from women to men were 2·61 per 100 person-years in couples in which women used hormonal contraception and 1·51 per 100 person-years in couples in which women did not use hormonal contraception (adjusted hazard ratio 1·97, 95% CI 1·12—3·45, p=0·02). Marginal structural model analyses generated much the same results to the Cox proportional hazards regression.
Interpretation Women should be counselled about potentially increased risk of HIV-1 acquisition and transmission with hormonal contraception, especially injectable methods, and about the importance of dual protection with condoms to decrease HIV-1 risk. Non-hormonal or low-dose hormonal contraceptive methods should be considered for women with or at-risk for HIV-1.
Funding US National Institutes of Health and the Bill & Melinda Gates Foundation.