Ivermectin for treatment of bancroftian filariasis in French Polynesia: efficacy in man, effect on transmission by vector Aedes polynesiensis
Cartel, J.L.; Sechan, Y.; Boutin, J.P.; Celerier, P.; Plichart, R.; Roux, J.F.
Tropical Medicine and Parasitology Official Organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit 41(3): 241-244
1990
ISSN/ISBN: 0177-2392 PMID: 2255839 Document Number: 361491
Forty male Polynesian Wuchereria bancrofti carriers, aged between 18 and 50 years, with microfilarial (mf) counts >=20/ml were treated with a single dose of ivermectin (50, 100, 150 or 200 micro g/kg). Following therapy, mf levels fell to <1% of pretreatment levels in the carriers treated with the 3 highest doses. After one month, negativization rate was 40% in patients treated with a 50 micro g/kg dose, significantly lower than in patients treated with higher doses. Recurrence of microfilaraemia 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 micro g/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 micro g/kg respectively. No significant difference was observed between mf levels by group at 6 and 12 months. With respect to efficacy, a dose >=100 micro g/kg appeared superior to 50 micro g/kg dose; no significant difference between the 3 highest doses was observed. Although some patients developed headache, myalgia and fever within 24 h following therapy, none of the adverse reactions was considered serious. In the vector A. 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. By reducing both the mf count in man and the L3 cephalic larvae load in vectors, ivermectin doses >=100 micro g/kg proved to be effective for treatment and control of bancroftian filariasis in French Polynesia. Forty male Polynesian Wuchereria bancrofti carriers with mf counts >=20/ml were treated with a single ivermectin 50, 100, 150 or 200 micro g/kg dose. Following therapy, mf levels fell to less that 1% of pretreatment levels in the carriers treated with the 3 highest doses. After 1 month, negativation rate was 40% in patients treated with 50 micro g/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 micro g/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 micro g/kg, respectively. No significant difference was observed between mf levels by group at 6 and 12 months. With respect to efficacy a dose >=100 micro g/kg appeared superior to 50 micro g/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 Aedes 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. By reducing both mf counts in man and L3 cephalic larvae load in vector, ivermectin doses >=100 micro g/kg, proved to be effective for treatment and control of filariasis due to W. bancrofti var. pacifica in French Polynesia.AS/D.C. Jenkins.