Efficacy of Higher Albendazole and Ivermectin Doses on Wuchereria Bancrofti Microfilarial Clearance in Malawi

Albendazole and ivermectin are currently used in combination for annual mass treatment of lymphatic filariasis in Africa. Although the drugs have been donated, the cost of such programmes is very high and has proven to be a major impediment to the success of programmes in many countries with limited financial resources. Data from albendazole treatment of other filarial infections and one study comparing single to multi-dose Diethycarbamazine/albendazole in lymphatic filariasis suggest that increased dose and/or frequency of albendazole dosing may be more effective in clearing microfilariae. It is essential to determine whether such higher doses are indeed beneficial since this could have far-reaching effects on the conduct and management of the main mass treatment programmes and also in the management of programmes as they near elimination.

The proposed study will enrol up to 120 volunteers with microfilaremic Wuchereria bancrofti infection who would be randomized to receive standard annual treatment (albendazole 400 mg + ivermectin 200 mcg/kg), annual treatment with an increased dose of albendazole (albendazole 800 mg + ivermectin 200400 mcg/kg) or semi-annual treatment with a standard (albendazole 400 mg + ivermectin 200 mcg/kg), or an increased albendazole dose (albendazole 800 mg + ivermectin 200 400 mcg/kg). Microfilarial levels, as well as measures of adult worm burden (circulating antigen) will be followed every six months for two years to determine whether the higher doses, or more frequent regimens are more effective. The data obtained would be used, in combination with the data from other similar studies being conducted in Mali and in India to advise the Global Programme for the Elimination of Lymphatic Filariasis (GPELF) on improved methods of treatment both for mass treatment and for the management of problem areas within the global programme.