The Global Programme to Eliminate Lymphatic Filariasis: Health Impact after 8 Years

Abstract

BackgroundIn its first 8 years, the Global Programme to Eliminate Lymphatic Filariasis (GPELF) achieved an unprecedentedly rapid scale-up: >1.9 billion treatments with anti-filarial drugs (albendazole, ivermectin, and diethylcarbamazine) were provided via yearly mass drug administration (MDA) to a minimum of 570 million individuals living in 48 of the 83 initially identified LF-endemic countries.MethodologyTo assess the health impact that this massive global effort has had, we analyzed the benefits accrued first from preventing or stopping the progression of LF disease, and then from the broader anti-parasite effects (‘beyond-LF’ benefits) attributable to the use of albendazole and ivermectin. Projections were based on demographic and disease prevalence data from publications of the Population Reference Bureau, The World Bank, and the World Health Organization.ResultBetween 2000 and 2007, the GPELF prevented LF disease in an estimated 6.6 million newborns who would otherwise have acquired LF, thus averting in their lifetimes nearly 1.4 million cases of hydrocele, 800,000 cases of lymphedema and 4.4 million cases of subclinical disease. Similarly, 9.5 million individuals—previously infected but without overt manifestations of disease—were protected from developing hydrocele (6.0 million) or lymphedema (3.5 million). These LF-related benefits, by themselves, translate into 32 million DALYs (Disability Adjusted Life Years) averted. Ancillary, ‘beyond-LF’ benefits from the >1.9 billion treatments delivered by the GPELF were also enormous, especially because of the >310 million treatments to the children and women of childbearing age who received albendazole with/without ivermectin (effectively treating intestinal helminths, onchocerciasis, lice, scabies, and other conditions). These benefits can be described but remain difficult to quantify, largely because of the poorly defined epidemiology of these latter infections.ConclusionThe GPELF has earlier been described as a ‘best buy’ in global health; this present tally of attributable health benefits from its first 8 years strengthens this notion considerably.

Global drivers of human pathogen richness and prevalence

“…Although we cannot preclude that other measures of disease control effort would have explained more variation, environmental variables alone account for the vast majority of the variation in pathogen richness. In theory, regional or even global eradication of diseases can be cheaper in the long run than more local disease control (Ottesen et al 2008), but in practice eradication successes are rare, with just one example of global eradication of a disease, that of smallpox (de Quadros 2002). The effect of disease control effort was far greater on human pathogen prevalence (table 2) than on richness.…”

Ivermectin disrupts the function of the excretory-secretory apparatus in microfilariae of Brugia malayi

“…LF treatment includes annual, single-dose combinations of either IVM or diethylcarbamazine with albendazole (ABZ). More than 1.9 billion treatments have been provided since 2000 through the Global Program for Elimination of LF (1,4).…”

“…HQ123446 and HQ123447). 1 To whom correspondence should be addressed. E-mail: timothy.g.geary@mcgill.ca.…”

Glutamate-gated Chloride Channels

“…The macrocyclic lactone (ML) group of anthelmintics, insecticides, and acaricides acts at GluCls, either activating the channels directly or potentiating their responses to glutamate (17,18). Worldwide sales of these products for animal health, agriculture, and fish farming are worth billions of dollars annually, and hundreds of millions of doses of ivermectin are given to people every year as part of the control and elimination programs for onchocerciasis and lymphatic filariasis (19,20). Insect GluCls are also partly responsible for the insecticidal activity of fipronil, as this compound blocks these channels in addition to its action at GABA receptors (21,22).…”