Elimination of lymphatic filariasis: The endgame and challenges for meeting the 2020 target

Abstract

Lymphatic filariasis (LF) is a major cause of acute and chronic morbidity and a significant impediment to socioeconomic development in 73middle and low income countries. The disease affects 120 million people and a further 1.4 billion are also at risk of acquiring the disease through exposure to mosquito bites. It has been estimated that eliminating LF can provide economic benefits in excess of US$22 billion over an 8-year period. The Global Programme to Eliminate Lymphatic Filariasis (GPELF) through the WHO strategy of preventive chemotherapy and transmission control (PCT), has targeted LF for elimination by 2020. This will be achieved mainly by mass drug administration (MDA) of albendazole in combination with either ivermectin or diethylcarbamazine citrate (DEC). PCT is a pro-poor strategy that enables regular and coordinated administration of safe, single-dosemedications. GPELF is one of the most rapidly expanding global health programs in the history of public health administeringmore than 540million treatments in 54 countries in 2012. The MDA campaign has been most effective in themiddle-income economies of Southeast Asia where all 15 endemic countries have initiated MDA. In Africa, only 18 of the 34 endemic countries were implementing MDA in 2012. Many of the communities in countries yet to start MDA for LF elimination are in hard to reach areas in post-conflict environments with poor health systems infrastructure. Following several annual rounds since GPELF was launched in 2000, many countries are now scaling downMDA activities after achieving 100% geographic coverage and instituting monitoring and evaluation procedures to establish the impact of several consecutive rounds of MDA and determine if transmission has been interrupted. At the same time, countries yet to initiate MDAwill have to adopt improved mapping and coverage assessment protocols to accelerate the efforts for achieving global elimination by 2020. There are other challenges have to be addressed if the 2020 target is to be achieved. Nevertheless, PCT presents an excellent platform for integrated control of other neglected tropical diseases (NTDs) where several diseases coexist, given that either or both ivermectin and albendazole are effective against onchocerciasis and soil-transmitted helminthiasis.