Global programme to eliminate lymphatic filariasis: progress report, 2017. Weekly Epidemiological Record. WHO, 2018
Lymphatic filariasis (LF) is a vector-borne neglected tropical disease (NTD) targeted for elimination as a public health problem. Infection with any of the 3 species of filarial parasites, Wuchereria bancrofti, Brugia malayi and B. timori, disrupts normal lymphatic vessel function and leads to chronic disabling consequences, manifest as hydrocele, lymphoedema and elephantiasis. The Global Programme to Eliminate Lymphatic Filariasis (GPELF) established by WHO aims to stop transmission and alleviate suffering among affected patients. WHO recommends feasible, cost-effective approaches to put an end to one of the world’s leading causes of avoidable disability.
Achievements in 2017
Validation of elimination as a public health problem
Elimination of LF as a public health problem means reducing infection prevalence in an area to below target thresholds and providing the recommended basic package of care in all areas with lymphoedema or hydrocele patients. A process of validation is used for formal confirmation of elimination as a public health problem.4 In a sign of continuing global progress against lymphatic filariasis, WHO acknowledged that the evidence documented in dossiers received from Egypt and Thailand in 2017 met the validation criteria.
Scale-up of mass drug administration
Mass drug administration (MDA) is the WHO-recommended preventive chemotherapy (PC) strategy to stop transmission of LF. MDA involves treatment of all eligible people living in all endemic areas with recommended, setting-specific regimens of the anthelminthic medicines ivermectin, diethylcarbamazine and albendazole (IDA). The smallest administrative unit that countries use as the basis for making decisions about implementing MDA is called the implementation unit (IU). MDA is no longer required when the prevalence of infection has been reduced to such low levels that transmission is no longer sustainable, preventing new infections. WHO recommends multiple rounds of MDA with effective coverage (more than 65% coverage of the total population consuming the medicines) prior to assessing impact on infection levels.