Preventing HIV in resource-limited settings: evidence for action, from cross-sectional surveys

Abstract

The current issue of the International Journal of Epidemiology features seven papers that cover a range of issues that are central to our understanding of the HIV epidemic and its control in resource-limited settings. One cross-sectional study highlights the importance of education as a protective factor against HIV in young South African women, another illustrates the complex relationship between socioeconomic position and HIV infection in Tanzania, and a further prevalence study examines the importance of lack of circumcision as a risk factor in the South Indian state of Andhra Pradesh. Male circumcision is also the topic of a modelling study and an accompanying commentary, which examine the potential long-term impact of male circumcision on HIV prevalence in sub-Saharan Africa. Another article in this issue systematically reviews the risk of HIV transmission from orogenital sex, and the final piece estimates the HIV prevalence in Dehong Prefectrue of Yunnan Province China, which is close to the ‘Golden Triangle’ and has a serious HIV epidemic, fuelled by injection drug use. Almost three decades (and a Nobel prize) after the discovery of the virus, HIV/AIDS continues to be a massive burden in many resource-limited settings. Young people aged 15–24 years account for almost half of all new HIV infections in adults, and subSaharan Africa remains the region most heavily affected by HIV. What can be done to stem the epidemic? Keep them in school, say Pettifor and colleagues, based on a nationally representative sexual behaviour and HIV testing survey in South Africa, which showed that not completing high school was the most important risk factor for HIV infection in young women. The authors focused on women aged 15–24 years who reported to have only one life-time partner, and therefore seemingly were at low risk of infection. The prevalence of HIV-1 infection was nevertheless high: 15.0% compared with 3.8% in men of the same age reporting one life-time partner. Over threequarters of women had not completed high school, and their HIV prevalence was 16.9% compared with 8.6% among the minority of women completing their education (crude odds ratio 2.15). The survey was cross-sectional and it is therefore unclear when women contracted HIV, before or after dropping out of school. Dropping out of school was clearly related to sociodemographic and behavioural factors, but unfortunately we are not told which of the variables included in the multivariable model were responsible for the substantial increase in the odds of infection associated with dropping out (adjusted odds ratio 3.75). The study of Pettifor and colleagues supports the notion that social policies which keep young women in school will have many benefits, including the prevention of HIV infection. Interestingly, a randomized evaluation comparing three school-based HIV/AIDS interventions in Kenya recently showed that reducing the cost of education by paying for school uniforms, but not training teachers in HIV/AIDS education, reduced dropout rates, teen marriages and teen pregnancies. The importance of education is questioned by the data from the 2003/2004 Tanzania HIV/Aids Indicator Survey (THIS). Mshisha and colleagues focussed on sexually active adults and found that while education was not associated with HIV infection, there was a positive association between standard of living and HIV infection: in women, the prevalence of HIV infection increased from 2.7% in the lowest category of the household standard of living index to 14.1% in * Corresponding author. E-mail: egger@ispm.unibe.ch 1 Institute of Social and Preventive Medicine, Finkenhubelweg 11, University of Bern, CH-3012 Bern, Switzerland. 2 Swiss Tropical Institute, Socinstrasse 57, University of Basel, CH-4002 Basel, Switzerland. Published by Oxford University Press on behalf of the International Epidemiological Association