THE most popular contraceptive in Kenya doubles the risk of women becoming infected with HIV, a new study shows. Use of the injectable contraceptive also increases the risk of HIV-positive women infecting their male partners. The results present a predicament for women because injectables and the pill are Kenya's most popular contraceptives, in part because women can keep them secret.
The study was published in the respected Lancet Infectious Diseases journal on Monday and involved 3,800 couples from Kenya, Uganda, Tanzania, Botswana, Rwanda, South Africa and Zambia. It was led by University of Washington but also included researchers from Kenyatta National Hospital, University of Nairobi and Moi University.
The study has prompted the World Health Organisation to convene a meeting next January to consider if evidence is now strong enough to advise women against injectable contraceptives. Two past studies showed similar results but researchers yesterday said the current study is the strongest. "We want to make sure that we warn when there is a real need to warn, but at the same time we don't want to come up with a hasty judgement that would have far-reaching severe consequences for the sexual and reproductive health of women," said Mary Lyn Gaffield, an epidemiologist in the World Health Organisation's department of reproductive health and research quoted in the New York Times.
Kenya's Ministry of Public Health says they are waiting for direction from the WHO. There may however be a policy change to promote alternative family planning solutions for women. Injectables have been the most popular form of contraception in Kenya and are used by 48 percent of married women, according to the 2008 Kenya Demographic and Health Survey.
About 16% of total users prefer the pill while women using implants account for about 14 percent of total users. The Lancet study says that women using hormonal contraception through injectables became infected at a rate of 6.61 per 100 person-years, compared with 3.78 for those not using them.
Transmission of HIV to men occurred at a rate of 2.61 per 100 person-years for women using hormonal contraception compared with 1.51 for those who did not. Researchers have been trying to explain the link between contraceptive use and HIV infection. They said it is possible hormonal contraception causes biological changes, such as changes to the cells that line the vagina or cervix and that influence susceptibility to HIV.
Renee Heffron, an epidemiologist and co-author of the study, however said research examining whether the hormone changes genital tissue or vaginal mucous had been inconclusive. "It could be that progestin in injectables causes immunologic changes in the vagina and cervix or could increase the HIV's ability to replicate," Charles Morrison, senior director of clinical sciences at FHI 360, an NGO whose work includes researching the intersection of family planning and HIV told the US media.
Researchers also found that there was more HIV in the genital fluid of those using hormonal contraception than those who were not, which could explain why men might have increased risk of infection from women using injectables. The researchers also found that oral contraceptives increased risk of HIV infection and transmission, but the number of pill users in the study was too small.
Others suggested that women on birth control often are careless in using condoms for protection. The study however recorded condom use, thus excluding the possibility that increased infection occurred because couples using contraceptives were less likely to use condoms. Injectable contraceptives in Kenya include Depo Provera. Pfizer, the US-based manufacturer of the branded version of Depo-Provera, declined to comment to the New York Times on the study, saying officials had not yet read it.
The study's authors however said the injectables used by the African women were probably generic versions. Depo Provera has never been approved for use as a contraceptive in the US. It is controversial because it reportedly can cause heavy bleeding, weight gain, headaches, nervousness and depression.