Global programme to eliminate lymphatic filariasis: progress report, 2019. Weekly Epidemiological Record. WHO, 2020
Lymphatic filariasis (LF) is an avoidable, debilitating, disfiguring disease caused by infection with the filarial parasites Wuchereria bancrofti, Brugia malayi and B. timori. Parasites nest in the lymphatic vessels, impair lymphatic function and lead to lymphoedema and hydrocoele. Mosquitos in the genera Culex, Anopheles, Mansonia and Aedes transmit the para-sites from person to person. In 2000, WHO established the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to stop transmission of infection with mass drug administration (MDA) and to alleviate suffering among people affected by the disease through morbidity management and disability prevention (MMDP).
Achievements in 2019
Validation of elimination as a public health problem
Kiribati, Malawi and Yemen submitted dossiers claiming elimination of LF as a public health problem. The dossiers from all 3 countries demonstrated reduction of the prevalence of infection in all endemic areas to levels below target thresholds for ≥4 years after MDA had been stopped and documented the availability and provision of essential care for persons with lymphoedema and hydrocoele. Therefore, WHO has acknowledged their achievements.
Scale-up of mass drug administration
WHO recommends setting-specific regimens of ivermectin, diethylcarbamazine and albendazole in different combinations to stop transmission of the parasites. MDA
involves treatment of all eligible people living in all endemic areas. An implementation unit (IU) is the smallest administrative unit that countries use as a basis for making decisions about implementing MDA.
The population in an IU no longer requires MDA when the prevalence of infection has been reduced to such low levels that transmission is considered no longer sustainable.1 Multiple rounds of MDA with effective coverage (≥65% coverage of the total population consuming the medicines) 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 determine whether levels of infection have decreased below target thresholds.