Neglected tropical diseases

Improved availability of new test to enhance global lymphatic filariasis elimination

5 February 2016 ¦ Geneva −− A new diagnostic test enabling countries to determine when to stop large-scale treatment of populations to eliminate lymphatic filariasis is now available. WHO is coordinating the procurement and supply of the new test for use in its Global Programme to Eliminate Lymphatic Filariasis (GPELF).

The Filariasis Test Strip (FTS) is a new point-of-care rapid diagnostic test designed to detect in human blood the antigen of the major species of filarial worm (Wuchereria bancrofti) that causes lymphatic filariasis.

Survey results using new test can determine the success of mass drug administration
© WHO/J. King

The test was developed by Alere (Scarborough, ME, United States) through a financial grant from the Bill & Melinda Gates Foundation. Pharmaceutical companies (Eisai Co., Ltd., GSK and MSD) donating the medicines needed to eliminate the disease are partnering also to contribute to funding the procurement of the test, which enables countries to know when elimination targets have been met.1

Until recently, BinaxNOW Filariasis was the only immunochromatographic test commercially available against Bancroftian filariasis infection. The FTS has been evaluated in more than 15 different settings in 11 countries and is now being used in WHO-recommended mapping, monitoring and evaluation activities.2

WHO’s recommended strategy in the GPELF relies on preventive chemotherapy, also referred to as mass drug administration (MDA), where entire population groups at risk of the disease are treated with anthelminthic medicines. Countries working towards eliminating the disease distribute medicines annually to entire communities during MDA.

At least five rounds of MDA are needed to reduce infections to levels below a threshold at which mosquitoes are unable to continue spreading the parasites from person to person and new infections are prevented. Diagnostic tests are necessary for conducting the WHO-recommended Transmission Assessment Survey (TAS) to determine when infections have been reduced below these target thresholds and MDA can stop.3,4

Resources to procure the FTS and implement TAS are a major limitation for many countries preparing to measure the impact of MDA. Providing the required diagnostic tests is complementary to ongoing commitments to implement MDA and TAS made by the governments of endemic countries, bilateral organizations including the United States Agency for International Development, the UK Department for International Development and the Japan International Cooperation Agency, as well as nongovernmental organizations and partners in the Global Alliance to Eliminate Lymphatic Filariasis. Globally, around 750,000 tests are expected to be distributed in more than 20 countries in 2016. Each unit of this new test costs US$1.50.

Improving the availability of the FTS will enhance global efforts to eliminate the disease.


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