Validation of the rapid assessment procedure for loiasis (RAPLOA) in the Democratic Republic of Congo.

Samuel Wanji,Peter J Diggle,Floribert Tepage,Jan H Remme,Maurice N Mutro,Tony O Ukety,Dowo O Akotshi

doi:10.1186/1756-3305-5-25

Abstract

BackgroundA simple method called RAPLOA, to rapidly assess what proportion of people in a community are infected with L. loa and hence which communities are at high risk of severe adverse reactions following ivermectin treatment, was developed in Cameroon and Nigeria. The method needed further validation in other geographical and cultural contexts before its application in all endemic countries. The present study was designed to validate RAPLOA in two regions in the North East and South West of the Democratic Republic of Congo.MethodsIn each study region, villages were selected from different bio-ecological zones in order to cover a wide range of loiasis endemicity. In each selected community, 80 people above the age of 15 years were interviewed for a history of eye worm (migration of adult L. loa under the conjunctiva of the eye) and parasitologically examined for the presence and intensity of L. loa infection. In total, 8100 individuals from 99 villages were enrolled into the study.ResultsThe results confirmed the findings of the original RAPLOA study: i) the eye worm phenomenon was well-known in all endemic areas, ii) there was a clear relationship between the prevalence of eye worm history and the prevalence and intensity of L. loa microfilaraemia, and iii) using a threshold of 40%, the prevalence of eye worm history was a sensitive and specific indicator of high-risk communities.ConclusionFollowing this successful validation, RAPLOA was recommended for the assessment of loiasis endemicity in areas targeted for ivermectin treatment by lymphatic filariasis and onchocerciasis control programmes.

Highlights

A simple method called Rapid Assessment Procedure for loiasis (RAPLOA), to rapidly assess what proportion of people in a community are infected with L. loa and which communities are at high risk of severe adverse reactions following ivermectin treatment, was developed in Cameroon and Nigeria
The risk of severe adverse reactions has been a major preoccupation for ivermectin treatment programmes throughout the central African subregion where L. loa coexists with Onchocerca volvulus [7]
8100 individuals were examined from 99 communities, of which were in South West Democratic Republic of Congo (DRC) and in North East DRC

Summary

Introduction

A simple method called RAPLOA, to rapidly assess what proportion of people in a community are infected with L. loa and which communities are at high risk of severe adverse reactions following ivermectin treatment, was developed in Cameroon and Nigeria. Each community itself is in charge of designing and implementing the ivermectin treatment [1] This strategy has been very successful and more than 65 million people in several reports from Cameroon indicated that high microfilaraemia of Loa loa may be associated with severe and sometimes fatal encephalopathic reactions in patients who had taken ivermectin against onchocerciasis [4,5,6]. The risk of severe adverse reactions has been a major preoccupation for ivermectin treatment programmes throughout the central African subregion where L. loa coexists with Onchocerca volvulus [7]. Several treatment programmes have been interrupted in Cameroon and the Democratic Republic of Congo (DRC)

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Results

Discussion

Conclusion