Combination ivermectin plus diethylcarbamazine, a new effective tool for control of lymphatic filariasis

In 1993, a three arm double-blind controlled trial was implemented in French Polynesia, to compare the tolerance and efficacy of single doses of the combination ivermectin (IVR) 400μg.kg^-1 plus diethylcarbamazine (DEC) 6 mg.kg^-1 vs. IVR 400μg.kg^-1 or DEC 6mg.kg^-1 alone, for treatment of Wuchereria bancrofti carriers. Of the 57 treated male patients in whom microfilaremia (mf) densities ranged from 22 to 4,709 mf/ml, three groups of 19 were randomly selected, and allocated to one of the three treatments. Twelve months after treatment 37%, 16% and 16% of patients were mf negative in groups DEC, IVR and IVR plus DEC respectively. Mf percent return to pretreatment level was significantly lower in the group IVR + DEC (1.9%) than for DEC 6 (14.7%) or IVR 400 (11.6%). Antigenemia percent return to pretreatment level was lower in the groups IVR + DEC or DEC 6 than for IVR 400. The combination IVR + DEC proved to be the most effective on macrofilariae and microfilariae (antigenemia and mf negative patients). The combination will be a very powerful tool for control of lymphatic filariasis. An annual filariasis day could be the most cost-effective strategy for administration of the drugs.