Global programme to eliminate lymphatic filariasis: progress report, 2021

Overview

Lymphatic filariasis (LF) is a preventable neglected tropical disease (NTD) caused by infection with the filarial parasites Wuchereria bancrofti, Brugia malayi or B. timori. Mosquitos in the genera Culex, Anopheles, Mansonia and Aedes transmit the parasites from person to person. Lymphoedema and hydrocoele are the visible, chronic clinical consequences of the impairment of lymphatic vessels caused by infection with these parasites. WHO established the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to stop transmission of infection by mass drug administration (MDA) of anthelminthics and to alleviate the suffering of people affected by the disease through morbidity management and disability prevention (MMDP). Since the start of GPELF, the number of infections has been reduced by 74% globally. The latest estimate is that 51.4 million people are infected. 

Achievements in 2021

Scale-up of mass drug administration

considered no longer sustainable.3 Multiple rounds of MDA with effective coverage (≥65% of the total population) are required to achieve the desired effect. WHO recommends sentinel and spot-check community surveys, followed by a transmission assessment survey (TAS) to measure the impact of MDA and to determine whether the level of infection has decreased below the target threshold. TAS is repeated twice during 4–6 years after cessation of MDA (TAS2 and TAS3) to ensure no recrudescence of LF infection considered no longer sustainable.3 Multiple rounds of MDA with effective coverage (≥65% of the total population) are required to achieve the desired effect. WHO recommends sentinel and spot-check community surveys, followed by a transmission assessment survey (TAS) to measure the impact of MDA and to determine whether the level of infection has decreased below the target threshold. TAS is repeated twice during 4–6 years after cessation of MDA (TAS2 and TAS3) to ensure no recrudescence of LF infection.