COMPARISON OF SINGLE-DOSE DIETHYLCARBAMAZINE AND IVERMECTIN FOR TREATMENT OF BANCROFTIAN FILARIASIS IN PAPUA-NEW-GUINEA

This double-blind study compared the clinical safety and parasitologic efficacy of single-dose regimens of diethylcarbamazine (DEC) and iver mectin for treatment of bancroftian filariasis in Papua New Guinea. Fi ve groups of 10 men each with mean levels of parasitemia ranging from 2,985 to 5,185 microfilariae (mf)/ml were given DEC (6 mg/kg/ of body weight one time or 1 mg/kg, then 6 mg/kg four days later) or ivermecti n (220 mug/kg; 20 mug/kg, then 200 mug/kg four days later or 20 mug/kg , then 400 mug/kg four days later). No significant side effects (e.g., acute adenolymphangitis, fever lasting more than eight hours, hypoten sion) were observed in any of the five treatment groups. The magnitude of reduction in microfilaremia was greater (P < 0.0 1) for the three ivermectin groups versus the two DEC groups in the first 30 days after drug administration (mf levels < 1% of pretreatment values versus 22. 6-41.5%, respectively). At 90 and 180 days, mf levels continued to dec rease in the DEC groups whereas they increased in the ivermectin group s given a total dose of 220 mug/kg. Eighteen months after drug adminis tration, individuals given DEC or 420 mug/kg of ivermectin had the gre atest degree of reduction in microfilaremia (86-90% compared with the pretreatment values). Decreases in parasite antigenemia measured by en zyme-linked immunosorbent assay for a secreted 200-kD adult worm antig en were greatest for the single-dose DEC group (39.7% decrease relativ e to the pretreatment level versus 7.8-15.7% for the ivermectin groups ). These results indicate that single-dose DEC and ivermectin are well -tolerated by Wuchereria bancrofti-infected individuals with high leve ls of microfilaremia. Both drugs lead to sustained reductions in micro filaremia up to 18 months after administration.