Eliminating lymphatic filariasis: a view from the field

Among infections closely associated with poverty, lymphatic filariasis (LF) is a study in contrasts. It is both a consequence of and a contributor to poverty. Although rarely fatal, it is recognized as a leading global cause of lifelong disability as well as significant personal, social, and economic burdens coincident with disease. Infection is often considerably more prevalent in communities than the number of cases of overt pathology for which LF is best known (lymphedema, elephantiasis, and hydrocele). With an estimated 120 million to 130 million affected persons in 83 countries and 1.25 billion persons living in areas at risk, in some countries LF may be expanding its range, whereas in others, with economic development, it has disappeared with little if any targeted intervention. The transmission cycle is relatively inefficient, yet an association with pockets of deepest poverty remains tenacious. Thanks to scientific advances in diagnostic tools, and particularly in control strategies focused on large-scale drug donation and mass drug distribution programs, scientists and policy makers now consider LF eliminable. Together with new approaches for morbidity control, a hopeful tone surrounds a disease problem that as recently as two decades ago could easily have been categorized as among the most neglected of neglected diseases. Continued progress toward global LF elimination will require solutions to potential obstacles in the most challenging--that is, the poorest--endemic settings. This chapter reviews progress toward LF elimination and some of the remaining challenges from a perspective in Haiti, the only least developed country of the Americas.