The Ugandan government’s decision to abolish tuition fees for school pupils, the resulting improved participation in education and an associated decline in adolescent sexual activity are responsible for substantial declines in HIV incidence and prevalence among teenage girls in the Rakai district, John Santelli and colleagues report in the January 14 edition of AIDS.
Across Africa, over a million adolescent girls are living with HIV. Whereas HIV rates are similar between boys and girls in younger age groups (with infections largely due to mother to child transmission), prevalence among girls aged 15 to 19 tends to be considerably higher than among boys of the same age.
UNAIDS argue that infection rates could be improved by reducing gender-based violence, ensuring access to quality health services, keeping girls in school and empowering young women and girls.
The data for the current study come from the rural Rakai district in the south-west of the country – a major site of HIV-related research, treatment programmes and prevention initiatives. A longitudinal cohort study has surveyed local residents on a semi-annual basis since the late 1980s, collecting demographic, behavioural and biological data, and tracking the factors associated with HIV infection.
In 2013, an analysis from this cohort identified a number of factors that were associated with new HIV infections among girls and young women, aged 15 to 24. An important one was not attending school, with current students much less likely to acquire HIV (in multivariate analysis, odds ratio 0.22, 95% confidence interval 0.07 – 0.72).
Other factors associated with new HIV infections were having been married but now separated from the partner; having two or more sexual partners in the past year; having had symptoms of a sexually transmitted infection; and living in a trading village rather than in a more isolated rural area. Of note, self-reported condom use or concurrent relationships were not associated with differences in the risk of infection.
Last year, an innovative study from this cohort found that compared with individuals who remain HIV negative, young people who have recently acquired HIV describe sexual relationships marked by poorer communication, greater suspicion and mistrust, and larger and more transitory sexual networks. The researchers pointed to poverty and gendered power relationships as deeper causes of these problems.
Declining prevalence and incidence
The most recently published analysis focuses on 22,164 participants aged 15 to 24 who took part in at least one survey between 1999 and 2011.
The prevalence of HIV infection among girls aged 15 to 19 steadily declined during this time, from 3.8% in 1999 to 2.0% in 2011 (p = <0.001). There were some fluctuations in HIV incidence (new infections), but whereas it was as high as 1.7% in the first survey, it had lowered to 0.6 and 0.2% in the two most recent surveys (p = 0.006).
Similar declines were not seen among women in a slightly older age band (20 to 24 years). Prevalence in this group was over 10% and incidence over 1.2% in most surveys.
Boys and young men had consistently lower rates of infection and this did not change between 1999 and 2011.
In 1997 – just before these data were collected – the Ugandan government introduced a policy of Universal Primary Education which abolished school fees. A similar policy for secondary education was introduced in 2007. This has resulted in much greater participation in education, although the influx of new students massively increased class sizes and sometimes lowered the quality of schooling.
In the Rakai cohort, the proportion of 15 to 19 year old girls attending school increased from 26 to 59% during the study.
At the same time, there were substantial declines in the proportion of adolescent girls who had had ever had sex (from 76 to 50% during the period of study) or had married (from 46 to 24%). Amongst those who were sexually experienced, the proportion reporting no sexual partners in the last year increased (from 7 to 12%) and the proportion with two or more partners decreased (from 11 to 6%).
There was a little improvement in the consistent use of condoms with primary partners, but a much greater change in the proportion of girls’ primary sexual partners who had been circumcised – unsurprising given that Rakai was the site of one of the major studies of circumcision for HIV prevention.
Of note, adolescent boys’ school attendance improved over the same time period, and boys were also less likely to report marriage, having had sex, having multiple partners or having concurrent sexual relationships. But HIV rates did not decline among boys, young men or young women – only among adolescent girls.
Moreover schooling appears to have protected girls in Rakai during their teenage years, but not into adulthood – new infections among women in their early twenties remained high.
The researchers’ modelling (a method known as hierarchical decomposition analysis) suggests that 29% of the decline in HIV incidence in adolescent girls can be attributed to fewer infections among girls who are sexually experienced. Of more importance, 71% of the decline in incidence can be attributed to the delay in sexual debut. Furthermore, this change was entirely attributed to the improvement in school attendance.
“Increases in school enrolment over time were concurrent with considerable declines in sexual experience among adolescent men and women,” the researchers say. “For adolescent women, much of this decline in HIV incidence was statistically attributable to reduced sexual experience and the decline in the sexual experience was entirely attributable to increasing levels of school enrolment.”
Whereas other interventions such as the availability of antiretroviral therapy and male circumcision could be expected to have an impact on infection rates, they should do so for males as well as females, and for individuals in their twenties too. The absence of changes in incidence in those groups supports the idea that schooling is a more likely explanation for reduced infections among teenage girls.
Another potential factor could be changes in the age of girls’ sexual partners. (Younger men are less likely to have HIV than older men). But there has been no change over time in the age of sexual partners.
“These data suggest that an effort to increase access to education may be important to future HIV prevention efforts among youth in Uganda and in other areas of sub-Saharan Africa,” the authors conclude. “However, the absence of a reduction in HIV acquisition among young adult men and women suggests that multiple HIV prevention efforts with youth are needed to reach the goal of an AIDS-free generation.”
Santelli JS et al. Trends in HIV acquisition, risk factors and prevention policies among youth in Rakai, Uganda, 1999–2011. AIDS 29: 211-19, 2015.