A community trial of ivermectin for onchocerciasis in Sierra Leone: compliance and parasitological profiles after three and a half years of intervention.
We have studied the compliance patterns and the long-term effects of repeated ivermectin at various dosing intervals in a randomized controlled trial. The setting for the trial was six neighbouring communities hyperendemic for onchocerciasis in southern Sierra Leone. A total of 335 subjects attended a survey 18 months after the fifth treatment round. Of those randomized to ivermectin, over 85% had received at least three doses. There was no evidence that women of childbearing age were consistently under-treated, despite the criteria for exclusion from treatment. An intention-to-treat analysis showed that a 6-monthly ivermectin treatment regime satisfactorily suppressed microfilarial loads. Microfilarial repopulation was significantly slower over an 18-month period after multiple doses compared to a single dose. Further analysis of microfilarial repopulation suggests that there is a cumulative suppressive effect after at least the first three doses of ivermectin, and that an annual treatment interval is as effective for short-term microfilarial suppression as a 6-monthly interval.
Whitworth
J A
JA
Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine, UK.
Downham
M D
MD
Lahai
G
G
Maude
G H
GH
D000293:Adolescent; D000328:Adult; D000969:Antinematodal Agents; D002648:Child; D005260:Female; D005369:Filaricides / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D007559:Ivermectin / Q000627:therapeutic use*; D008297:Male; D009855:Onchocerciasis / Q000188:drug therapy* / Q000469:parasitology; D010349:Patient Compliance; D012008:Recurrence; D012807:Sierra Leone; D016896:Treatment Outcome
D000969:Antinematodal Agents; D005369:Filaricides; D007559:Ivermectin