RANDOMIZED PLACEBO-CONTROLLED COMPARISON OF IVERMECTIN AND ALBENDAZOLE ALONE AND IN COMBINATION FOR WUCHERERIA-BANCROFTI MICROFILAREMIA IN HAITIAN CHILDREN

Background Lymphatic filariasis and intestinal helminth infections are important disorders in tropical areas. Periodic treatment with albend azole is now used in many school-based intestinal helminth-control pro grammes. However, few such programmes exist for lymphatic filariasis, despite evidence that single-dose treatment with ivermectin can greatl y reduce the concentration of Wuchereria bancrofti microfilariae in th e blood for months to years. We aimed to assess the potential for scho ol-based control of lymphatic filariasis by investigating the efficacy and tolerability of combined ivermectin and albendazole in Haitian sc hoolchiidren. Methods in January, 1996, we collected 832 20 mu L capil lary blood samples for inclusion in a randomised controlled study from children aged 5-11 years, and examined them by microscopy for W bancr ofti microfilariae. Infected children were randomly assigned treatment with placebo (n=29), a single 200-400 mu g/kg dose of ivermectin (mea n, 273 mu g/kg, n=28), 400 mg albendazole (n=29), or a combination of 200-400 mu g/kg ivermectin and 400 mg albendazole (n=24). Children wit h high concentrations of microfilariae in the blood were admitted to h ospital and adverse reactions were monitored for 3-5 days, otherwise c hildren were examined at school or during a visit to their home. 4 mon ths after treatment, we examined blood samples again for microfilariae . Findings 113 microfilaraemic children were enrolled (mean age 7.8 ye ars). 4 months after treatment, the proportion of children who remaine d positive for microfilariae was significantly lower in the ivermectin plus albendazole group (four [17%]), but there were no significant ch anges in the other three groups (20 [69%] placebo, 22 [76%] albendazol e alone, 17 [61%] ivermectin alone remained positive; p=0004). Geometr ic mean microfilarial concentration decreased from 9.3 to 5.3 per 20 m u L blood among children who received placebo; from 15.5 to 1.5 per 20 mu L blood among those who received ivermectin only (p=0.032); from 1 4.1 to 5.1 per 20 mu L blood among those who received albendazole alon e; and from 13.7 to 0.3 per 20 mu L blood among those who received bot h ivermectin and albendazole (p=0.0001). Systemic adverse reactions di d not differ significantly between the four groups. Interpretation For children with W bancrofti microfilaraemia, combined treatment with iv ermectin and albendazole was more effective than treatment with iverme ctin only, with no measurable increase in severity of adverse reaction s.