Societal variables are central to effective HIV intervention models
Editor - Nagelkerke et al. (1) model the impact of interventions to prevent HIV transmission in India and Botswana to provide evidence for policy-making. Behavioural interventions focused on sex workers, treatment of sexually transmitted infections, mother-to-child transmission, and highly active antiretroviral therapy (HAART) for female sex workers and the entire infected population. In this model, HAART targeted at sex workers would have limited sustained effectiveness among sex workers in contrast to behavioural interventions which would drive the epidemic to extinction in India.
While Nagelkerke et al. outline many assumptions underpinning their model, they do not acknowledge the heterogeneity of the HIV epidemic across India. India has multiple HIV epidemics which are driven by distinct patterns of risk and vulnerability (2) and these are, in turn, driven by diverse social and economic factors. It is the disparity in these societal variables which renders assumptions about the extent of risk and the effectiveness of any intervention across the country problematic.
Whilst modelling can aid in priority-setting, the authors must rely on assumptions and simplified characterizations of complex realities which carry significant ramifications for the validity of the results and HIV prevention policy in general. For example, such assumptions include the targeting of sex workers in sites where condom promotion and distribution may be feasible. Some interventions with brothel-based sex workers in India have achieved remarkable success in reducing risk behaviours (3). In many areas of India, however, sex workers operate from home or on the streets and are less easily reached by public health interventions - including condom promotion or HAART. Sex work remains illegal in India and police may consider possession of condoms by women as evidence of sex work. Similarly, interventions using HAART require a functioning health care system. In India, over 75% of outpatient care is in the private sector, much of which is described as "low quality" and provided by "untrained practitioners" (4).
There is increasing recognition of the importance of addressing societal factors to curb the HIV epidemic (5). Over (6) has suggested that eight societal variables explain more than half of the differences in urban HIV prevalence between countries. Understanding societal variables (such as caste, gender relations, power in sexual relationships, etc.) may help in determining the future spread of the epidemic and contribute to explaining the local effectiveness of public health interventions - such as programmes to reduce risk for sex workers.
In addition to targeted behaviour change interventions, the HIV epidemic in India may be contained through a multisectoral approach that takes into account the highly diverse nature of behavioural, social and economic risk and vulnerability. Improved understanding of the contribution of societal variables is necessary in order to produce models that reflect the impact of addressing these variables on overall HIV incidence in India. n
Conflicts of interest: none declared.
1. Nagelkerke NJD, Jha P, de Vlas SJ, Korenromp EL, Moses S, Blanchard JF, et. al. Modelling HIV/AIDS epidemics in Botswana and India: impact of interventions to prevent transmission. Bulletin of the World Health Organization 2002;80:89-96.
2. Hawkes S, Santhya KG. Diverse realities: sexually transmitted infections and HIV in India. Sexually Transmitted Infections. In press 2002.
3. Jana S, Bandyopadhyay N, Mukherjee S, Dutta N, Basu I, Saha A. STD/HIV intervention with sex workers in West Bengal, India. AIDS 1998; 12 (Suppl B):S101-8.
4. Raising the sights: better health systems for India's poor. Washington (DC): World Bank; 2001. Report No. 22304.
5. Sumartojo E. Structural factors in HIV prevention: concepts, examples, and implications for research. AIDS 2000;14 (Suppl)1:S3-10.
6. Over M. The effects of societal variables on urban rates of HIV infection in developing countries: an exploratory analysis. In: Ainsworth M, Fransen N, Over M, editors. Confronting AIDS: evidence from the developing world. Washington (DC): World Bank; 1998.
1 Assistant Director of Health Services (AIDS), Kerala State AIDS Control Society, India.
2 Honorary Lecturer, London School of Hygiene and Tropical Medicine, London, England.