The third paper in The Lancet Series on Neglected Tropical Diseases (NTDs) looks at the issues facing integration/co-implementation of preventive chemotherapy strategies. The paper is written by Dr Margaret Baker, RTI International, Washington, DC, USA, and colleagues.
The authors say: "These issues include identification of the most cost-effective ways to rapidly map areas at high risk of neglected tropical diseases, establishment of the most appropriate monitoring systems, and development of post-intervention surveillance strategies as the programmes for lymphatic filariasis, onchocerciasis, and trachoma reach the elimination phase."
The team examined current policies for mapping, monitoring, and surveillance of NTD and note that, if advantage is to be taken of scaled up interventions to address NTDs, efforts to develop rapid, inexpensive, and easy-to-use methods—whether disease-specific or integrated—should be increased.
Detailed mapping information is needed to allow planning for implementation, and the authors identify several successful mapping strategies that have incorporated quick, simple, and cheap methodology—the African Programme for Onchocerciasis Control developed the rapid epidemiological mapping of onchocerciasis (REMO) risk assessment instrument, on the basis of the proximity of probable Simulium breeding sites. They also highlight several innovative approaches for mapping integration—in Cameroon, rapid assessment procedures for loaisis and rapid epidemiological assessment surveys for onchocerciasis were co-implemented; and In Ethiopia, combined malaria and trachoma surveys have shown that prevalence estimates, indicators, and risk factors for both diseases could be obtained for the cost of undertaking one disease survey.
For monitoring, the authors say progress towards integration lies in standardisation of definitions of coverage and creation of agreed common reporting forms that will enable comparability of data across countries and diseases. They also call for new indicators to be created so that donors can closely monitor programme success—eg, the total number of treatments delivered through the preventive chemotherapy approach and the percentage of people at risk of these diseases reached would be useful for advocacy purposes.
Surveillance is clearly vital to declare any NTD programme's success. The authors highlight as an example the lymphatic filariasis programmes, in which the immunochromatographic card test is the recommended instrument for assessment of progress towards elimination endpoints, especially when used to assess cohorts of children born since the intervention began. This approach has been used in Egypt, and will be widely implemented as other countries seek to stop their mass drug administration and move towards surveillance.
The authors conclude: "Although full integration of all elements of mapping, monitoring, and surveillance strategies for the diseases targeted through the preventive chemotherapy approach is not feasible, there could be many opportunities for integrated strategies when integration is the best option."
The final paper in the Series is by Dr Lesong Conteh, London School of Hygiene and Tropical Medicine, UK, and colleagues. The paper discusses the human and financial toll of NTDs—which claim some 500,000 lives each year and cause an estimated 57 million disability-adjusted life years (DALYs).
The authors discuss the catastrophic out-of-pocket expenses faced by poor families when seeking treatment for NTDs. They cite the example of Buruli ulcer in Ghana—treatment for which can cost two-and-a-half times the household's annual earnings. Failure to seek treatment can have a knock-on effect on the ability of the productive household members to work, further compounding the poverty cycle. In Egypt, workers with schistosomiasis benefited from improved quality of life and increased productivity if they could access early detection and treatment.
Many NTD programmes, such as those for onchocerciasis and lymphatic filariasis, achieve high coverage and are cost effective. Having taken into account the long-term donations of ivermectin for onchocerciasis and lymphatic filariasis, albendazole for lymphatic filariasis, and azithromycin for trachoma, the total cost of treatment of all those infected is often less than US$0.50 per person treated annually—cheap compared to costs of treating HIV, tuberculosis, and malaria.
The authors examine NTD in terms of economies of scale. Up to a certain point, increasing the programme size reduces the cost per treatment, but there comes a point when going above maximum capacity can make costs increase again. A successful example is the African Programme for Onchocerciasis Control, which, together with national health services and non-governmental development organisations, has ensured the distribution of ivermectin (donated by Merck) in 19 African countries, using a network of more than 261,000 community-directed distributors spanning over 217,000 communities. This coverage (40 million treatments in 2005) enabled not only those living near health facilities to benefit from the treatment but also the populations most vulnerable and difficult to reach (in terms of remoteness and conflict) to receive annual treatments.
Integration opportunities are discussed, including the rationale of combining NTD control with programmes for HIV/AIDS, tuberculosis, and malaria (economies of scope). A multisite study in Nigeria, Cameroon, and Uganda showed that in districts where home management of malaria was integrated with onchocerciasis-related community-directed intervention (a dose of ivermectin per year), many more children received antimalarial treatment than they did in areas with home-based management alone. Bednet uptake also increased.
The authors conclude: "Success in the control of these diseases has been the result of concerted and focused efforts to adopt strategies that are some of the most cost-effective public health interventions... Several highly cost-effective interventions exist to control various neglected tropical diseases. It is now important to investigate how additional efficiency gains can be achieved by exploiting economies of scope and confirming neglected tropical disease control as one of the best value-for-money health interventions."
Dr Margaret Baker, RTI International, Washington, DC, USA. T) +1 202 687 4497 E) mcb93@georgetown.edu
Dr Lesong Conteh, London School of Hygiene and Tropical Medicine, UK, contact via e-mail E) lesong.conteh@lshtm.ac.uk
Professor David Molyneux, Liverpool School of Tropical Medicine, UK. T) +44 (0) 7780 991 824 E) David.Molyneux@liverpool.ac.uk
For both Series papers, see: http://press.thelancet.com/ntd3and4.pdf
Journal
The Lancet