This week's edition of The Lancet sees the first in a four-part Series on Neglected Tropical Diseases (NTDs) -- conditions which almost exclusively affect the world's poorest people, namely those 2.7 billion people living on less than $US 2 per day. This first paper is written by Dr Bernhard Liese, Department of International Health, Georgetown University, Washington, DC, USA, and colleagues.
Lymphatic filariasis, onchocerciasis (river blindness), soil-transmitted helminthiasis, schistosomiasis, and trachoma are the five most common NTDs, and there are many more—causing, in total, around half-a-million deaths and 57 million disability-adjusted life years each year.
The authors say: "Social stigma, prejudice, marginalisation, extreme poverty of afflicted populations, and low mortality are several factors contributing to the neglect of these diseases. Their prevalence in specific geographical and environmental conditions outside the developed world and their insignificant market share for pharmaceutical business further reduces these diseases' prominence in the global health debate."
Furthermore, they point out that, while an exclusive innovative financing mechanism was set up for HIV/AIDS, malaria, and tuberculosis in the form of the Global Fund, funding for NTDs remained limited to a few donors. Control initiatives for NTDs also differ significantly in terms of their origins, geographic coverage, epidemiological goal, stakeholders involved, funding, and governance structure.
The authors point out the success of onchocerciasis control, which remains one of the longest continuous international disease control efforts. Initially based on larvicide spraying by helicopter to control the larvae of Simulium (blackfly) vectors in the rivers of 11 west African countries in 1987, it moved to include a mass drug administration component when the pharmaceutical company Merck provided its drug ivermectin (Mectizan) free of charge as long as needed. The programme was concluded in 2002, resulting in the elimination of onchocerciasis from large parts of west Africa and freeing up 250 000 km² of arable land.
The authors say: "No other public health initiative has benefited from the availability of donated drugs to such an extent as have neglected tropical diseases...Such cooperation between the industry and programmes for neglected tropical diseases is a good example of a public-private partnership."
Integration of national activities targeting NTDs, plus coordination of fragmented governance structures, are vital if progress is to made in tackling these conditions. The authors say: "An exploratory meeting of crucial stakeholders—modelled after the well regarded Rockefeller Foundation Bellagio meetings—to identify shared goals and the areas in which collaboration could improve outcomes, as well as exploring strategy, structure, membership of a larger alliance, could be important next steps to ensure momentum and sustainability of the present advocacy for these diseases."
They add: "Immediate coordination of governance arrangements is needed between the supporting international contributors of neglected tropical diseases for national programmes that are based on preventive chemotherapy and transmission control. Such programmes have been forcefully supported by the Bill & Melinda Gates Foundation and recently by the US Agency for International Development, sometimes including complex trachoma control, yet they are organisationally diverse and their governance arrangements are strongly affected by funding source and donor requirements."
This first paper in the Series also discusses the opportunities to co-implement mass drug distribution for NTDs with programmes such as those tackling malaria, HIV, and tuberculosis, and also vitamin A distribution. The authors say: "Co-implementation of mass drug administration with home-based management of malaria and distribution of longlasting bednets, or combination of mass drug administration with intermittent preventive treatment, has shown remarkable interactions."
They conclude: "Most importantly, the present momentum in putting neglected tropical diseases on the global health agenda needs to be maintained, which includes not only increased advocacy and funding but also the establishment of consensus across stakeholders on definitions, objectives, and strategies."
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