Conclusion
Tropical diseases are often viewed as neglected, because the investments made to fight them appear negligible compared with the massive amounts expended globally on the health problems of developed countries. Tropical diseases are truly diseases of the poor, but despite the limited resources available for research and control, simple and effective interventions have been developed and delivered to populations in need for the four tropical diseases discussed in this chapter. Thus, experience with these four diseases sends a powerful message: success is possible, even for neglected tropical diseases of poor populations in developing countries. Elimination of these diseases as public health problems can be achieved, and investments in tropical disease research and control can make a significant contribution to poverty reduction.
An important reason for the success was that the interventions were extremely cost-effective. The available cost-effectiveness data, though limited, show convincingly that intervention against these diseases is a good investment, and the argument for investment gets better when other economic benefits, not reflected in DALYs, are taken into account, such as increased food production when fertile land along river valleys became available for agriculture after the control of onchocerciasis in West Africa and increased labor productivity after effective filariasis control in India.
The pharmaceutical industry also played a major role through large drug donations, and the creation of intercountry control programs provided effective mechanisms for implementing interventions, technical support, and coordination. Another reason for the success was a focused research program that ensured the development of interventions based on simple and sustainable approaches that use cheap and "appropriate" technology and that are potentially multifunctional.
Chagas disease, LF, onchocerciasis, and leprosy are now on target for elimination as public health problems from large parts of the world. However, these diseases cannot be eradicated using current tools, and much remains to be done to expand and sustain the control efforts and undertake the necessary research to improve the control efforts as well as to develop more definite solutions. It will be essential, therefore, that donors and ministries of health not abandon these programs because of their success.
