PITTSBURGH (PA, USA) – Women represent more than half of those infected with HIV worldwide. In sub-Saharan Africa the figure reaches 60% and such a high rate of infection occurs in a context where women’s fertility rate is also high compared to the developed world. Pregnancy is therefore a critical issue when reseearching and responding to the HIV epidemics but little is known about the impact of pregnancy on HIV transmission and results are contradictory.

However, for the first time, a research team has investigated in a large study the impact of pregnancy on the horizontal transmission of HIV from pregnant women to their male sexual partner and from men to pregnant women. The research presented at the Microbicides 2010 conference in Pittsburgh by Nelly Mugo from the Partners in Prevention HSV/HIV transmission Team showed that pregnancy doubled the risk of a woman to transmit HIV to her male partner (Pregnancy is associated with an increased risk for HIV transmission among African HIV-1 serodicordant couples. N. Mugo and coll.).

The study was conducted at 14 sites in 7 Southern African countries and recruited more than 3,300 serodiscordant couples (i.e. couple in which one of the partner is HIV+ and the other HIV-). Roughly a third of the women were HIV negative in a relationship with an HIV+ partner and two-third were HIV+ in a relationship with an HIV negative partner. After a 24 months follow up, the study observed that 64 women acquired HIV of which 17 (26.6%) during their pregnancy, whilst 57 men were infected of which 12 (21.1%) occurred during their partner’s pregnancy.

Whilst the risk of male-to-female infection during pregnancy was not statistically different from the risk of infection outside pregnancy (after correction for a series of factors) “Pregnancy in female HIV-1 infected partners was associated with increased female-to-male HIV-1 Transmission risk” the study concluded.

This is the first study showing that pregnancy increased the risk of female-to-male transmission and it has some important consequences. The first is that it supports further the importance of providing ARV to HIV-infected pregnant women. The second is that it reveals an ignored component of Prevention of Mother to Child (PMTCT): men. Indeed, PMTCT focuses on vertical transmission from the mother to the child, but ignored horizontal transmission from the mother to her sexual partner(s).

Though the theoretical risk of female-to-male transmission is lower than that of male-to-female by a factor of 2 (it is less in low income country and the overall risk varies according to numerous factors) the researcher’s observation indicates that pregnancy is an important factor in HIV transmission.

Most importantly, the research highlights the fact that researchers, activists, advocates, and health professionals need to end “thinking in silos”. This has been a recurrent theme since the start of the conference. There is a growing feeling that HIV prevention needs to bring down the wall erected around various parts of the “vulnerable populations” and start thinking transversally, beyond labels, across populations and behaviours. The research presented clearly suggests that PMTCT needs now to take into account men and maybe should be re-branded PMTCTSP to include Sexual Partners.

As research and understanding progress, it is becoming clearer that the compartmentalisation of HIV prevention and tunnel vision are having a detrimental effect on its success. A holistic, combinatorial approach to HIV prevention is now clearly needed, echoing the theme of the M2010 conference “Bridging bridges in HIV prevention” across disciplines, populations, behaviours and people.

Percentage of pregnant women with HIV receiving antiretrovirals to prevent MTCT, by region, 2004-2008

Related posts brought to you by Yet Another Related Posts Plugin.