Single-dose treatment of Wuchereria bancrofti infections with ivermectin and albendazole alone or in combination: evaluation of the potential for control at 12 months after treatment

The effect of single-dose ivermectin (150-200 mu g/kg) and albendazole (400 mg) treatment alone and in combination on Wuchereria bancrofti microfilara emia, antigenaemia and clinical manifestations was compared 12 months after treatment in a double-blind placebo-controlled field trial carried out in Ghana in 1996-98, to evaluate the potential of these treatments for control . Both ivermectin and combination treatments resulted in pronounced reducti ons in microfilaraemia among individuals who were microfilaria positive bef ore treatment. Among individuals who were positive for circulating filarial antigen before treatment, antigen levels increased considerably over the 1 -year period after treatment in the placebo group, whereas they decreased i n the ivermectin and combination groups. However, the post-treatment differ ence reached statistical significance in neither microfilaraemia nor antige naemia between the ivermectin and the combination groups. Albendazole treat ment alone showed only a minor effect on microfilaraemia and antigenaemia. No effect of the treatments on the incidence of new cases of microfilaraemi a or antigenaemia, or on clinical manifestations, was observed. Both iverme ctin and combination treatment thus appeared effective for control of W. ba ncrofti infections, but the difference in efficacy between the 2 treatments after 12 months appeared to be minimal.