Neglected tropical diseases

WHO recommends triple drug therapy to accelerate global elimination of lymphatic filariasis

3 November 2017 | Geneva -- The World Health Organization (WHO) is recommending an alternative three drug treatment to accelerate the global elimination of lymphatic filariasis - a disabling and disfiguring neglected tropical disease.

The treatment, known as IDA, involves a combination of ivermectin, diethylcarbamazine citrate and albendazole. It is being recommended annually in settings where its use is expected to have the greatest impact.

This new regimen will help to improve programmatic impact and lead to the ultimate elimination of lymphatic filariasis in many regions where millions of people are at risk of contracting the disease” said Dr Soumya Swaminathan, Director-General of the Indian Council of Medical Research who was involved in the study in India.

Evidence from recent research studies has demonstrated that adding ivermectin to the currently recommended combination of diethylcarbamazine citrate plus albendazole clears microfilaria more efficiently from the blood than the two-drug regimen and is equally safe.

Large randomized community studies conducted in four countries1 found that IDA is as safe as the two-drug regimens when used during MDA. The specifics of the new recommendations are published in WHO’s new guideline

Up to 24 countries currently using diethylcarbamazine citrate plus albendazole could benefit from IDA, and its use will be particularly helpful to endemic countries that have not yet started MDA in all endemic districts.

Progress

Significant progress towards global elimination of lymphatic filariasis as a public health problem has already been made with the existing regimens.

Of the 72 countries endemic for lymphatic filariasis, 20 have been able to reduce levels of infection below elimination thresholds and stop MDA. Furthermore, WHO has already validated ten countries2 as having eliminated lymphatic filariasis as a public health problem.

At least 856 million people are living in areas where filarial infections are still transmitted; up to 514 million people are living in areas that could benefit from IDA, providing a potential fast-track and low-cost option to accelerate elimination.

Need for compliance

The effectiveness of MDA in at-risk communities depends on all eligible individuals consuming the medicines.

Having a more effective combination regimen means we need to overcome poor compliance,” said Dr Jonathan King, Scientist in-charge of lymphatic filariasis elimination at WHO’s Department of Control of Neglected Tropical Diseases. “What is required now are wide-ranging communication and delivery approaches to maximize community participation during MDA campaigns. National programmes will have to re-evaluate the performance of existing strategies and engage at-risk communities.

The disease

Lymphatic filariasis is caused by infection with parasitic worms living in the lymphatic system. The larval stages of the parasite (microfilaria) circulate in the blood and are transmitted from person to person by mosquitoes.

Manifestation of the disease after infection takes time and can result in an altered lymphatic system, causing abnormal enlargement of body parts, and leading to severe disability and social stigmatization of those affected.

The parasites are transmitted by four main types of mosquitoes: Culex, Mansonia, Anopheles and Aedes.

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1Haiti, India, Indonesia and Papua New Guinea.
2Cambodia, Cook Islands, Maldives, Marshall Islands, Niue, Sri Lanka, Thailand, Togo, Tonga and Vanuatu.


Ashok Moloo
WHO/HTM/NTD
Telephone: +41 22 791 16 37
Mobile phone: +41 79 540 50 86
molooa@who.int