Reducing HIV in young women is essential for the Aids response in Africa, writes Professor Salim Abdool Karim.
Despite the scale-up of antiretroviral (ARV) therapy and HIV-prevention strategies, HIV prevalence among adolescent girls and young women in the country remains alarmingly high - and reflects high prevalence in this group within the general population.
Until we address infection in this key age group, progress in reducing the overall disease burden will remain limited.
By examining HIV prevalence of pregnancies among the 15 to 24-year-olds visiting antenatal clinics for the first time in the rural area of Vulindlela, KwaZulu-Natal, over 12 years, we found that instead of declining HIV prevalence had risen from 35.3 percent in the years 2001 to 2003 before ARVs were available to 39 percent in years from 2004 to 2008 when ARVs were becoming available and reaching 39.3 percent in the years 2009 to 2013 when the roll-out of ARVs got into full swing.
While prevalence in teenagers showed a small, but encouraging, decline - from 22.5 percent to 17.2 percent - over the same period, data revealed the risk of HIV infection increased threefold if their male partners were more than five years older. In generalised epidemic settings, such as South Africa, HIV prevalence in the 15 to 24 age group has come to be regarded as a useful indirect measure for the number of and trends in new infections.
In fact, in high HIV-burden environments, such as Vulindlela, HIV-infection rates increase very shortly after sexual debut - from 16 years onwards.
Assuming HIV transmission is highest during early and acute HIV infection, teens and young women infected can fuel the HIV epidemic in a particular community and South Africa, a country which still has the world’s highest number of Aids cases - estimated by the Joint UN Programme on HIV/Aids in 2012 to be 6.1 million.
This means that although the roll-out of ARVs in 2004 has had a substantial effect on survival, age-specific HIV-prevalence stands out as a clear explanation for the lack of progress in reducing the overall disease burden.
Understanding the disease and its transmission drivers for this group is thus seen as central to the design of additional interventions targeted specifically at teenagers and young women.
We know that the communities in which the study was conducted face enormous economic and social challenges.
The consistently high burden of HIV infection borne by young pregnant women in this rural community may be explained at least in part by young women engaging in high-risk sexual intercourse, which is frequently of a contractual nature and fuelled by the need for financial support.
Surveys identify an urgent need to understand the causality of these relationships and how they are evolving over time.
To what extent are these partnerships affected by the need for financial support in young women, or by the higher levels of illness and death in women over 25 years?
There may also be other complex cultural factors at play - all of which are as yet undetermined and require more focused analysis.
What we do know is that teenage girls are a key group for HIV prevention and understanding of HIV transmission dynamics in this population is a major gap in the knowledge of HIV.
Of major concern, given the negative effect on economic and educational levels of the mother, is the burden of teenage pregnancies in the community. The data shows that teenage pregnancies constituted an average of 30 percent of all pregnancies surveyed from 2001 to 2013.
The persistence of this high-teen pregnancy rate comes against the backdrop of several, largely government-initiated and school-based behavioural interventions and educational outreach programes that target the teenage female population.
These include initiatives aimed at delaying sexual debut, preventing intergenerational sex, medical male circumcision, promoting condom use within the structured ABC guidelines (abstinence, being faithful to one’s partner, and condom use), and even with earlier access to ARVs, which has been shown to prevent HIV transmission in randomised clinical trials and observational cohorts.
However, as the data reveals, measures have enjoyed limited success in reducing both pregnancy and HIV-infection rates in this challenging age group.
In addition to understanding the drivers of teenage pregnancies and age-disparate relationships, however, monitoring the impact of the provision of ARVs and the survival of women over 25 years continues to be critical.
The high burden of HIV observed in older groups reï‚ects the cumulative effect of HIV acquisition, underscores the extent of the care burden, and may help inform future prevention and treatment efforts.
Although HIV prevalence in South Africa varies widely by province and the generalisability of results is limited, the studies in KwaZulu-Natal starkly demonstrate the unprecedented scale of the HIV epidemic at a local level.
They also reveal unequivocal and unambiguously high pregnancy rates.
So what next?
Given the eight to 10-year delay between HIV infection and Aids-related morbidity and mortality, the continued scale-up of Antiretroviral therapy services at primary health care clinics remains one of the best chances we have of averting a further Aids catastrophe in this setting.
However, in addition, it is imperative that we undertake research in teenage girls - one of our highest risk populations - to examine both HIV incidence and the reasons why they have a high risk of HIV infection.
In this way we raise the chances of designing and implementing age-specific, targeted interventions that can make an impact on the epidemic where others thus far have failed.
The upcoming Aids conference in Durban gives us a valuable opportunity to learn from others what has worked in this population and to identify prevention gaps that might address the challenges presented by teenage girls and young women.
We neglect this group of young people at our peril.
* Salim S Abdool Karim is professor of Global Health in Epidemiology: Columbia University, director at the Centre for the Aids Programme of Research in South Africa and pro vice-chancellor (research) a the University of KwaZulu-Natal.
** The views expressed here are not necessarily those of Independent Media.
Sunday Tribune