Global programme to eliminate lymphatic filariasis: progress report, 2022

Overview

Lymphatic filariasis (LF) is a preventable mosquito-borne infectious disease targeted for global elimination as a public health problem. Infection with one of the filarial parasites, Wuchereria bancrofti, Brugia malayi and B. timori, impairs the lymph vessels, where the worms nest, later manifesting as hydrocoele, lympheodema and elephantiasis, resulting in unnecessary physical and mental suffering. 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). 

Achievements in 2022

Scale-up of mass drug administration

Despite a 74% reduction in global infections since 1997, 51.4 million people were estimated to be infected in 2018. Because infection and transmission in a community often go undetected, MDA is the recommended cost–effective strategy for treating all infected people living in endemic areas and for preventing further transmission. Operationally, MDA is conducted in an implementation unit (IU), the smallest administrative unit of a country used for treatment campaigns. The population of an IU no longer requires MDA when the prevalence of infection has been reduced to such a low level that transmission is considered no longer sustainable. Multiple rounds of MDA with effective coverage (≥65% of the total population) are required. WHO recommends sentinel and spot-check community surveys, followed by a transmission assessment survey (TAS) to measure whether the prevalence of infection is below the target thresholds and MDA can be stopped. TAS is repeated twice during 4–6 years after cessation of MDA (TAS2 and TAS3) to ensure no recrudescence of LF infection to levels that require intervention.