Unwanted surprise: Hormonal contraception facilitates HIV transmission

Public health officials in sub-Saharan Africa, where HIV remains prevalent, may soon find themselves in another predicament: The results of a new study published in The Lancet Infectious Diseases warns that women who use injectable hormone contraceptives double their risk of becoming infected with HIV. In addition, HIV-positive women increase the risk that their male sexual partners will become infected with the virus as well.

This news is especially problematic because injectable contraceptives are the most popular contraceptive used by women in the study area, where preventing unintended pregnancies is a major objective. But the study s lead author emphasizes the importance of also using barrier contraception, including dual protection with condoms and non-hormonal and low-dose hormonal methods for women who have HIV or are at risk of infection.

The study followed nearly 3,800 heterosexual couples in seven African countries, focusing exclusively on instances in which only one partner was HIV-positive. Even after accounting for condom use, researchers found that the increased infection rate was a result of the hormonal treatment and not simply due to lack lack of barrier protection.

Why, then, did the HIV infection rate of women using this mode of birth control double? Study authors believe there may be a physiological explanation: Injectable contraceptives may make women more vulnerable to HIV because the progestin found in the shot causes changes in the genital tissue or vaginal mucus, increasing the virus s ability to replicate.

According to study author Dr. Jared Baeten, an epidemiologist and infectious disease specialist, researchers found a higher concentration of HIV present in the genital fluid of infected women using hormonal contraception which might also explain why men are at a greater risk of infection as well.

ACSH's Dr. Gilbert Ross emphasizes the need to increase the use of barrier methods of contraception, including condoms.