To eliminate lymphatic filariasis (LF) as a public health problem, it is necessary to stop the spread of infection. Levels of worm larvae (microfilaria) in the blood of infected persons must be reduced so that mosquitoes cannot transmit the worms from one human to another. The strategy for interrupting transmission is an annual administration of two drugs for at least five years in a method known as mass drug administration (MDA). During an MDA campaign, the preventive chemotherapy treatment is given to as large a proportion of the population as possible in areas were LF is endemic.
CNTD’s support for MDA campaigns varies from country to country, depending on need and any support being provided by other partners. It covers operational planning, drug forecasting, logistics and supply chain management, training for staff and drug distributors involved in the campaign well as technical support during the campaign itself and afterwards to monitor impact and verify the level of coverage that has been achieved.
Preventive chemotherapy drugs:
The two alternative regimens are: single doses of albendazole (400mg) plus Mectizan® (150-200 mg/kg/body wt) or single doses of albendazole (400mg) plus DEC (6mg/kg/body wt).
DEC, developed over 50 years ago, is an inexpensive and effective anti-filarial drug which is used to treat LF in many countries. DEC is available in tablet form and in a fortified salt formulation for daily intake at meal times. However, DEC cannot be used in most of Africa because severe side reactions can occur when other infections, such as onchocerciasis (river blindness) are also present.
Mectizan® (generic name: ivermectin) is an oral anti-parasitic drug, discovered and developed by Merck & Co. Inc. which is effective against both LF and onchocerciasis. Mectizan® is provided free of charge by Merck & Co. Inc. for the treatment of onchocerciasis in all endemic countries and for LF in African countries where onchocerciasis and LF co-exist.
Albendazole, donated by GlaxoSmithKline for LF prevention, is a well-established anti-parasitic treatment, given to an estimated 500-800 million people, mostly children, for intestinal infections over the past 20 years. The combination of albendazole with either Mectizan® or DEC has been proven to enhance the efficacy of the individual-drug treatments in reducing the numbers of parasites in the blood.