In 2019, 538.1 million people were treated for lymphatic filariasis (LF) in 38 countries that implemented mass drug administration (MDA) of populations at risk of the disease, as recommended by the World Health Organization (WHO). Seventeen countries achieved the criteria for elimination of LF as a public health problem; Kiribati, Malawi and Yemen were the latest to be acknowledged by WHO.
The Global Programme to Eliminate Lymphatic Filariasis (GPELF) has delivered over 8.2 billion cumulative treatments to more than 923 million people since 2000. The treatments target the parasites in the blood of infected people and prevent the risk of transmission in the community. Infections have been brought to such low levels in some areas that 649.1 million people no longer require MDA for this debilitating parasitic disease.
Setting sights on 2030
The target set by GPELF in 2000 to eliminate LF as a public health problem globally by 2020 will not by achieved by then. Despite setbacks due to COVID-19, WHO will accelerate work to achieve this target by 2030. New global estimates suggest a 74% reduction in the number of infected people since the start of GPELF.2 The new, ambitious targets for 2030 are that 80% of endemic countries have met the criteria for validation of elimination as a public health problem, with the remaining 20% under post-treatment surveillance, meaning that MDA will no longer be required.
GPELF aims to reduce the prevalence of infection below target thresholds and to alleviate the suffering of people affected by lymphoedema and hydrocele, the chronic manifestations of the disease. The recommended essential package of care for managing lymphoedema and hydrocele should be available in 100% of districts where people are living with these manifestations. This goal is aligned with the aims of universal health coverage to leave no one behind by 2030. Reporting of LF morbidity improved again in 2019, showing that countries are addressing this aim and planning services for people affected by the disease.
Accelerate with a better combination of medicines
In 2017, WHO published a new guideline on alternative MDA regimens to eliminate LF and recommended a combined regimen of ivermectin, diethylcarbamazine citrate and albendazole (IDA) to accelerate the impact of MDA on transmission of the parasites.2 In 2019, IDA was used to treat 45.2 million people in 11 countries. In India, IDA was extended from four to 16 districts to treat more than 41 million people.
Risks to success
Currently, only six of 17 countries validated as having eliminated LF as a public health problem report surveillance activities. Without robust post-validation activities, transmission can remain undetected and the number of infections can resurge to previous levels. Countries are willing to conduct surveillance and remain vigilant, but programmes require clear guidance and resources. Additional research and better diagnostics are necessary to design more detailed, standardized methods for surveillance.
Further details of the progress made by GPELF in 2019 are reported in the Weekly Epidemiological Record.3
1 Cromwell EA, Schmidt CA, Kwong KT, Pigott DM, Mupfasoni D, Biswas G, et al 2020. The global distribution of lymphatic filariasis, 2000–18: a geospatial analysis. Lancet Glob Health. 2020;8:e1186–94.
2Guideline. Alternative mass drug administration regimens to eliminate lymphatic filariasis. Geneva: World Health Organization: 2017.
3Global programme to eliminate lymphatic filariasis: progress report, 2019. Wkly Epidemiol Rec. 2000;95:509–524.