Ivermectin for treatment of bancroftian filariasis in French Polynesia: efficacy in man, effect on transmission by vector Aedes polynesiensis

Abstract

Forty male Polynesian W. bancrofti carriers with mf counts greater than or equal to 20/ml were treated with a single ivermectin 50, 100, 150 or 200 mcg/kg dose. Following therapy, mf levels fell to less than 1% of pretreatment levels in the carriers treated with the 3 highest doses. After one month, negativation rate was 40% in patients treated with a 50 mcg/kg dose, significantly lower than in patients treated with higher doses. Recurrence of microfilaremia was observed by 3 months, mf recurrence percentages were significantly lower in patients treated with the 3 highest doses than in patients treated with a 50 mcg/kg dose. At 6 months, mf recurrence percentages reached 49.8, 12.6, 14 and 5.4% of pretreatment levels in carriers treated with 50, 100, 150 and 200 mcg/kg, respectively. No significant difference was observed between mf levels by group at 6 and 12 months. With respect to efficacy, a dose greater than or equal to 100 mcg/kg appeared superior to 50 mcg/kg dose; no significant difference between the 3 highest doses was observed. Some patients developed headache, myalgia and fever within 24 hours following therapy, none of adverse reactions were considered serious. In vector Ae. polynesiensis fed on carriers 6 months after treatment, average numbers of mf ingested and average numbers of L3 cephalic larvae were lower than those observed in mosquitoes fed on non-treated carriers with comparable mf counts.(ABSTRACT TRUNCATED AT 250 WORDS)