Social research on neglected diseases of poverty: continuing and emerging themes.

Abstract

Neglected tropical diseases (NTDs) exist and persist for social and economic reasons that enable the vectors and pathogens to take advantage of changes in the behavioral and physical environment. Persistent poverty at household, community, and national levels, and inequalities within and between sectors, contribute to the perpetuation and re-emergence of NTDs. Changes in production and habitat affect the physical environment, so that agricultural development, mining and forestry, rapid industrialization, and urbanization all result in changes in human uses of the environment, exposure to vectors, and vulnerability to infection. Concurrently, political instability and lack of resources limit the capacity of governments to manage environments, control disease transmission, and ensure an effective health system. Social, cultural, economic, and political factors interact and influence government capacity and individual willingness to reduce the risks of infection and transmission, and to recognize and treat disease. Understanding the dynamic interaction of diverse factors in varying contexts is a complex task, yet critical for successful health promotion, disease prevention, and disease control. Many of the research techniques and tools needed for this purpose are available in the applied social sciences. In this article we use this term broadly, and so include behavioral, population and economic social sciences, social and cultural epidemiology, and the multiple disciplines of public health, health services, and health policy and planning. These latter fields, informed by foundational social science theory and methods, include health promotion, health communication, and heath education. Social science health researchers have attended particularly to HIV/AIDS, and more recently to malaria and tuberculosis (TB), reflecting the prevalence and resistance to control of these diseases and their emphasis in the United Nations Millenium Development Goals. Other infectious diseases, by default, have slipped into a “neglected” category. These include most “tropical” diseases, such as Chagas disease, dengue, human African trypanosomiasis, leishmaniasis, leprosy, lymphatic filariasis, schistosomiasis, and onchocerciasis. The inclusion of these diverse diseases as “neglected” refers not only to their status relative to HIV, TB, and malaria. Their neglect reflects their epidemiology: they are prevalent among the poorest and most marginalized of the world's population. More than 70% of countries and territories affected by NTDs are low-income and lower middle-income countries, and 100% of low-income countries are affected by at least five NTDs [1]. This is due to multiple factors, including the focality of most NTDs and hence the localization of vulnerability, morbidity, and mortality. Various social determinants (e.g., poverty, gender, education, and migration) interact to establish local patterns of co-morbidity of NTDs and other pertinent public health problems (e.g., malnutrition, malaria, diarrheal diseases, and violence). These vulnerable populations tend to lack the power to draw attention from decision makers to their problems and to attract resources, and national resources tend to be directed to high prevalence, epidemic conditions at the expense of endemic diseases. NTDs also attract little research nationally or internationally, and virtually no investment or commercially based research and development in wealthy research settings [2]. In recent years, however, NTDs have received increasing international interest, partly in response to promising advances in drug development. Concerted efforts are being made also to promote innovative public health approaches such as integrated delivery of multiple interventions [3]–[5], which require research effort into effective public health interventions. This article was stimulated by the renewed interest in populations affected by NTDs and in feasible ways to prevent and control NTDs. Rather than focusing on specific medically defined NTDs, in this article, we focus on neglected diseases of poverty, i.e., diseases that disproportionately affect poor and marginalized or, in other words, diseases of “neglected” populations. We begin with a summary of the history of social research activities supported by the Special Programme for Research and Training in Tropical Diseases (TDR) at the World Health Organization (WHO). We then highlight the ongoing and emerging challenges to sustain and extend research to improve the control of NTDs, all of which are also neglected diseases of poverty. We identify emerging research priorities and reflect on the challenges in mainstreaming these issues in research and disease control programs, drawing attention to the urgency of particular research questions.