Global programme to eliminate lymphatic filariasis: progress report, 2023

Overview

Lymphatic filariasis (LF) is a vector-borne disease in humans caused by infection with the filarial parasites Wuchereria bancrofti, Brugia malayi and B. timori. Infections damage the lymphatic vessels and impair vessel function, leading to clinical manifestations such as lymphoedema and hydrocele. 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 2023

MDA is the recommended, cost–effective strategy for stopping transmission by treating all people living in areas in which infections are prevalent.1 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. To measure whether the prevalence of infection is below the target thresholds and MDA can be stopped, WHO recommends a strategy of sentinel and spot-check community surveys, followed by more robust surveys, the transmission assessment survey (TAS) or the ivermectin (I), diethylcarbamazine (D) and albendazole (A) (IDA) impact survey (IIS). These surveys should be repeated for 4–6 years after stopping MDA to ensure no recrudescence of LF infection. The results of these surveys in each endemic IU and documentation of the quality of care for people with lymphoedema and hydrocele is required for validation, by which WHO reviews and acknowledges a claim of having achieved elimination of LF as a public health problem.