Sustaining control of schistosomiasis mansoni in moderate endemicity areas in western Côte d’Ivoire: a SCORE study protocol

Abstract

BackgroundSchistosomiasis is a parasitic disease that occurs in the tropics and subtropics. The mainstay of control is preventive chemotherapy with praziquantel. In Africa, an estimated 230 million people require preventive chemotherapy. In western Côte d’Ivoire, infections with Schistosoma mansoni are widespread. To provide an evidence-base for programme decisions about preventive chemotherapy to sustain control of schistosomiasis, a 5-year multi-country study with different treatment arms has been designed by the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) and is currently being implemented in various African settings, including Côte d’Ivoire.Methods/DesignWe report the study protocol, including ethics statement and insight from a large-scale eligibility survey carried out in four provinces in western Côte d’Ivoire. The study protocol has been approved by the ethics committees of Basel and Côte d’Ivoire. A total of 12,110 children, aged 13–14 years, from 264 villages were screened for S. mansoni using duplicate Kato-Katz thick smears from single stool samples. Among the schools with a S. mansoni prevalence of 10-24%, 75 schools were selected and randomly assigned to one of three treatment arms. In each school, three stool samples are being collected from 100 children aged 9–12 years annually and one stool sample from 100 first-year students at baseline and in the final year and subjected to duplicate Kato-Katz thick smears. Cost and coverage data for the different intervention arms, along with environmental, political and other characteristics that might impact on the infection prevalence and intensity will be recorded in each study year, using a pretested village inventory form.DiscussionThe study will document changes in S. mansoni infection prevalence and intensity according to different treatment schemes. Moreover, factors that determine the effectiveness of preventive chemotherapy will be identified. These factors will help to develop reasonable measures of force of transmission that can be used to make decisions about the most cost-effective means of lowering prevalence, intensity and transmission in a given setting. The gathered information and results will inform how to effectively sustain control of schistosomiasis at a low level in different social-ecological contexts.Trial registrationISRCTN99401114 (date assigned: 12 November 2014).

Sustaining the Control of Schistosoma mansoni in Western Côte d'Ivoire: Baseline Findings Before the Implementation of a Randomized Trial

“…7 To strengthen the current evidence base for program decisions about preventive chemotherapy to gain and sustain the control of schistosomiasis, the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE; http://score .uga.edu/) designed a multi-country study with several treatment arms implemented over multiple years. 9,10 In contrast to other schistosomiasis-endemic parts of the world where considerable progress in the fight against schistosomiasis has been achieved over the past decades (e.g., Brazil and China), 11,12 control efforts in sub-Saharan Africa were less successful, partially explained by low coverage and rapid reinfection rates after MDA campaigns.…”

“…[15][16][17][18] This article describes the baseline parasitologic situation and village characteristics of the 75 communities in western Côte d'Ivoire that were randomized to one of the three intervention arms of a SCORE study to determine the effect of different treatment schedules to sustain schistosomiasis control in moderate endemicity areas. 9 In each school, some 100 children (usually 9-12 years) submitted three consecutive stool samples that were subjected to duplicate Kato-Katz thick smears each. We also compared our S. mansoni prevalence data with results from a previous large-scale eligibility survey while screening 50 children aged 13-14 years with a single stool sample subjected to duplicate Kato-Katz thick smears.…”

The spatial distribution of Schistosoma mansoni infection in four regions of western Côte d’Ivoire

“…In conclusion, pursuing a Bayesian geostatistical analysis using a large set of georeferenced S. mansoni prevalence data from a SCOREeligibility survey (Assaré et al, 2014) allowed risk profiling of S. mansoni in four regions of western Côte d'Ivoire. The generated risk maps have already been utilised by the national schistosomiasis control programme.…”

“…After receiving consent from the headmaster, teachers prepared class lists, including name, age and sex of all children. In each school, we aimed at selecting 50 children attending grades 4-6, as described elsewhere (Assaré et al, 2014). In brief, children aged 13 years and above were selected from grades 4-6 until the number of children reached 50.…”

“…The data were obtained from a large-scale eligibility survey conducted as part of a sustaining schistosomiasis control project requested by the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) (Assaré et al, 2014). The risk maps already proved useful for the national schistosomiasis control programme in Côte d'Ivoire.…”