Spatial risk prediction and mapping of Schistosoma mansoni infections among schoolchildren living in western Côte d'Ivoire

The objectives of this study were (1) to examine risk factors for Schistosoma mansoni infection among schoolchildren living in western Côte d'Ivoire, and (2) to carry forward spatial risk prediction and mapping at non-sampled locations. First, demographic and socio-economic data were obtained from 3818 children, aged 6–16 years, from 55 schools. Second, a single stool sample was examined from each child by the Kato-Katz technique to assess infection status of S. mansoni and its intensity. Third, remotely sensed environmental data were derived from satellite imagery and digitized ground maps. With these databases a comprehensive geographical information system was established. Bayesian variogram models were applied for spatial risk modelling and prediction. The infection prevalence of S. mansoni was 38·9%, ranging from 0% to 89·3% among schools. Results showed that age, sex, the richest wealth quintile, elevation and rainfall explained the geographical variation of the school prevalences of S. mansoni infection. The goodness of fit of different spatial models revealed that age, sex and socio-economic status had a stronger influence on infection prevalence than environmental covariates. The generated risk map can be used by decision-makers for the design and implementation of schistosomiasis control in this setting. If successfully validated elsewhere, this approach can guide control programmes quite generally.

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BAYESIAN SPATIAL RISK PREDICTION OF SCHISTOSOMA MANSONI INFECTION IN WESTERN CÔTE D’IVOIRE USING A REMOTELY-SENSED DIGITAL ELEVATION MODEL

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.2007.76.956 ◽

2007 ◽

Vol 76 (5) ◽

pp. 956-963 ◽

Cited By ~ 37

Author(s):

CHRISTIAN BECK-WÖRNER ◽

PENELOPE VOUNATSOU ◽

GIOVANNA RASO ◽

GERGELY RIGO ◽

ELIÉZER K. N’GORAN ◽

...

Keyword(s):

Schistosoma Mansoni ◽

Digital Elevation Model ◽

Risk Prediction ◽

Cote D'ivoire ◽

Côte D’Ivoire ◽

Remotely Sensed ◽

Cote D’Ivoire ◽

Spatial Risk ◽

Digital Elevation ◽

Elevation Model

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

Geospatial health ◽

10.4081/gh.2015.345 ◽

2015 ◽

Vol 10 (1) ◽

Cited By ~ 10

Author(s):

Rufin K. Assaré ◽

Ying-Si Lai ◽

Ahoua Yapi ◽

Yves-Nathan T. Tian-Bi ◽

Mamadou Ouattara ◽

...

Keyword(s):

Spatial Distribution ◽

Schistosoma Mansoni ◽

Cote D'ivoire ◽

Land Surface ◽

Côte D’Ivoire ◽

Environmental Data ◽

Sub Saharan Africa ◽

Cote D’Ivoire ◽

Public Health Burden ◽

Côte D'ivoire

Schistosomiasis poses a considerable public health burden in sub- Saharan Africa and a sound understanding of the spatial distribution facilitates to better target control interventions. The objectives of this study were i) to assess the prevalence of Schistosoma mansoni among school-aged children in four regions of western Côte d’Ivoire; ii) to determine demographic, climatic and environmental factors that influence the distribution of S. mansoni; and iii) to map and predict the distribution of S. mansoni in non-sampled locations. Parasitological surveys were carried out in 264 schools from June to December 2011. In each school, we aimed to examine 50 children for S. mansoni infection using duplicate Kato-Katz thick smears. Schools were georeferenced using a hand-held global positioning system receiver. Demographic data were obtained from readily available school lists, while climatic and environmental data were extracted from open-access remote sensing databases. Multivariable, binary non-spatial models and a Bayesian geostatistical logistic regression model were used to identify demographic, climatic and environmental risk factors for S. mansoni infection. Risk maps were developed based on observed S. mansoni prevalences and using Bayesian geostatistical models to predict prevalences at non-sampled locations. Overall, 12,462 children provided a sufficiently large stool sample to perform at least one Kato-Katz thick smear. The observed overall prevalence of S. mansoni infection was 39.9%, ranging from 0 to 100% at the unit of the school. Bayesian geostatistical analysis revealed that age, sex, altitude and difference between land surface temperature at day and night were significantly associated with S. mansoni infection. The S. mansoni risk map presented here is being been used by the national schistosomiasis control programme for spatial targeting of praziquantel and other interventions.

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Combining multi-criteria decision analysis with GIS approaches for decentralized organic wastes composting plants site selection in Tiassalé, Southern Côte d’Ivoire

Waste Management & Research ◽

10.1177/0734242x211038173 ◽

2021 ◽

pp. 0734242X2110381

Author(s):

Dotanhan Yeo ◽

Kouassi Dongo ◽

Eliachie Larissa Eméline Angoua ◽

Adeline Mertenat ◽

Phillipp Lüssenhop ◽

...

Keyword(s):

Decision Analysis ◽

Cote D'ivoire ◽

Site Selection ◽

Côte D’Ivoire ◽

Geographical Information ◽

Basic Field ◽

Cote D’Ivoire ◽

Multi Criteria Decision Analysis ◽

Côte D'ivoire ◽

The City

In recent years, decentralized composting appeared as one of the most appropriate treatment options for organic waste valorization in low- and middle-income countries. In Cote d’Ivoire, a pilot project has proved the feasibility of organic municipal solid waste composting for the city of Tiassalé. However, numerous issues still need to be addressed for the establishment of a sustainable decentralized composting system in this city. One of the key issues is site selection. Until now, there is no clear model for such plant site selection. In this study, multi-criteria decision analysis (MCDA) and geographical information system (GIS) approaches were combined to develop an appropriate model for selecting decentralized composting sites in the city of Tiassalé. The methodology used involved two different and complementary phases. First, MCDA and GIS techniques were used to identify the most suitable site areas. Seven criteria clustered in three main factors (environmental, social and economic), and five constraints were considered in the analysis process. Second, five sites were selected within the most suitable areas after a basic field visit and ranked using the Analytic Hierarchy Process. The results showed that the most suitable spaces for decentralized composting plant siting represent only 2.6% of the study area. The investigation yielded on the selection of the two best options for decentralized composting plant siting for the city of Tiassalé. This study proved that the combination of MCDA and GIS is a practical and efficient method to identify suitable sites for decentralized composting plants.

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Accuracy of Two Circulating Antigen Tests for the Diagnosis and Surveillance of Schistosoma mansoni Infection in Low-Endemicity Settings of Côte d’Ivoire

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.21-0031 ◽

2021 ◽

Author(s):

Rufin K. Assaré ◽

Mathieu I. Tra-Bi ◽

Jean T. Coulibaly ◽

Paul L. A. M. Corstjens ◽

Mamadou Ouattara ◽

...

Keyword(s):

Schistosoma Mansoni ◽

Cote D'ivoire ◽

Côte D’Ivoire ◽

Point Of Care ◽

Urine Specimen ◽

Cote D’Ivoire ◽

Côte D'ivoire ◽

Circulating Antigen ◽

Antigen Tests ◽

True Infection

In low-endemicity settings, current tools for diagnosis and surveillance of schistosomiasis are often inaccurate in detecting true infection. We assessed the accuracy of an up-converting phosphor lateral flow circulating anodic antigen (UCP-LF CAA) test and a point-of-care circulating cathodic antigen (POC-CCA) urine cassette test for the diagnosis of Schistosoma mansoni. Our study was conducted in eight schools of western Côte d’Ivoire. Fifty children, aged 9 to 12 years, were enrolled per school. From each child, a single urine specimen and two stool specimens were collected over consecutive days for diagnostic workup. Urine samples were subjected to UCP-LF CAA and POC-CCA tests. From each stool sample, triplicate Kato-Katz thick smears were examined. Overall, 378 children had complete data records. The prevalence of S. mansoni, as assessed by six Kato-Katz thick smears, was 4.0%. The UCP-LF CAA and POC-CCA tests revealed S. mansoni prevalence of 25.4% and 30.7%, respectively, when considering trace results as positive, and prevalence of 23.3% and 10.9% when considering trace results as negative. In the latter case, based on a composite gold standard, the sensitivity of UCP-LF CAA (80.7%) was considerably higher than that of POC-CCA (37.6%) and six Kato-Katz thick smears (13.8%). The negative predictive value of UCP-LF CAA, POC-CCA, and six Kato-Katz thick smears was 92.8%, 79.8%, and 74.1%, respectively. Our results confirm that UCP-LF CAA is more accurate than Kato-Katz and POC-CCA for the diagnosis of S. mansoni in low-endemicity settings.

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