Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania
There is a need for diagnostic techniques which are sensitive, specific, rapid and easy to perform at the point-of-care. The aim of this study was to evaluate the diagnostic performance of the Circulating Cathodic Antigen (POC-CCA) assay for Schistosoma mansoni in four schools along the coast of Lak...
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doaj-ab14d1fc323f4456b1bbfb923e6acb3e2020-11-25T03:24:01ZengElsevierParasite Epidemiology and Control2405-67312016-06-011210511510.1016/j.parepi.2016.04.002Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, TanzaniaMiriam Casacuberta0Safari Kinunghi1Birgitte J. Vennervald2Annette Olsen3Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, University of Copenhagen, Dyrlaegevej 100, DK-1870 Frederiksberg C, DenmarkNational Institute for Medical Research (NIMR), Mwanza Research Centre, Mwanza, Tanzania)Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, University of Copenhagen, Dyrlaegevej 100, DK-1870 Frederiksberg C, DenmarkParasitology and Aquatic Diseases, Department of Veterinary Disease Biology, University of Copenhagen, Dyrlaegevej 100, DK-1870 Frederiksberg C, DenmarkThere is a need for diagnostic techniques which are sensitive, specific, rapid and easy to perform at the point-of-care. The aim of this study was to evaluate the diagnostic performance of the Circulating Cathodic Antigen (POC-CCA) assay for Schistosoma mansoni in four schools along the coast of Lake Victoria in Mwanza Region, Tanzania, and to optimize the reading of the POC-CCA test lines by using a computer software image analysis. Initially, a pilot study in 106 school children indicated that time of urine collection did not have an impact on CCA results as 84.9% (90) had identical scores from a urine collected in the morning and a urine taken at midday after drinking 0.5 L of water. The main study was conducted among 404 school children (aged 9–12 years) where stool and urine samples were collected for three consecutive days. For S. mansoni diagnosis, stool samples were examined for eggs with duplicate Kato-Katz smears, whereas urine samples were tested for presence of antigen by POC-CCA. The proportion of positive individuals for S. mansoni by one POC-CCA was higher compared to two Kato-Katz smears (66.1% vs. 28.7%; p < 0.0001). Both proportions increased expectedly when three POC-CCAs were compared to six Kato-Katz smears (75.0% vs. 42.6%; p < 0.0001). Three POC-CCAs were more sensitive (94.7%) than six Kato-Katz smears (53.8%) using the combined results of three POC-CCAs and six Kato-Katz smears as the ‘gold standard’. To optimize the reading of the POC-CCA, a Software tool (Image Studio Lite®) was used to read and quantify the colour (expressed as pixels) of the test line on all positive tests, showing a positive correlation between number of pixels and the visually scored intensities and between number of pixels and egg counts. In conclusion, the POC-CCA assay seems to be a more appropriate tool for S. mansoni diagnosis compared to the Kato-Katz method in endemic communities such as Mwanza Region. Optimization of the tool in terms of cassette-reading could be assessed by computer software which was able to quantify the colour of the lines in the strip of the cassette.http://www.sciencedirect.com/science/article/pii/S2405673115300775Schistosoma mansoniSchool childrenCCAComputer image analysesTanzania |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Miriam Casacuberta Safari Kinunghi Birgitte J. Vennervald Annette Olsen |
spellingShingle |
Miriam Casacuberta Safari Kinunghi Birgitte J. Vennervald Annette Olsen Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania Parasite Epidemiology and Control Schistosoma mansoni School children CCA Computer image analyses Tanzania |
author_facet |
Miriam Casacuberta Safari Kinunghi Birgitte J. Vennervald Annette Olsen |
author_sort |
Miriam Casacuberta |
title |
Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania |
title_short |
Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania |
title_full |
Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania |
title_fullStr |
Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania |
title_full_unstemmed |
Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania |
title_sort |
evaluation and optimization of the circulating cathodic antigen (poc-cca) cassette test for detecting schistosoma mansoni infection by using image analysis in school children in mwanza region, tanzania |
publisher |
Elsevier |
series |
Parasite Epidemiology and Control |
issn |
2405-6731 |
publishDate |
2016-06-01 |
description |
There is a need for diagnostic techniques which are sensitive, specific, rapid and easy to perform at the point-of-care. The aim of this study was to evaluate the diagnostic performance of the Circulating Cathodic Antigen (POC-CCA) assay for Schistosoma mansoni in four schools along the coast of Lake Victoria in Mwanza Region, Tanzania, and to optimize the reading of the POC-CCA test lines by using a computer software image analysis. Initially, a pilot study in 106 school children indicated that time of urine collection did not have an impact on CCA results as 84.9% (90) had identical scores from a urine collected in the morning and a urine taken at midday after drinking 0.5 L of water. The main study was conducted among 404 school children (aged 9–12 years) where stool and urine samples were collected for three consecutive days. For S. mansoni diagnosis, stool samples were examined for eggs with duplicate Kato-Katz smears, whereas urine samples were tested for presence of antigen by POC-CCA. The proportion of positive individuals for S. mansoni by one POC-CCA was higher compared to two Kato-Katz smears (66.1% vs. 28.7%; p < 0.0001). Both proportions increased expectedly when three POC-CCAs were compared to six Kato-Katz smears (75.0% vs. 42.6%; p < 0.0001). Three POC-CCAs were more sensitive (94.7%) than six Kato-Katz smears (53.8%) using the combined results of three POC-CCAs and six Kato-Katz smears as the ‘gold standard’. To optimize the reading of the POC-CCA, a Software tool (Image Studio Lite®) was used to read and quantify the colour (expressed as pixels) of the test line on all positive tests, showing a positive correlation between number of pixels and the visually scored intensities and between number of pixels and egg counts. In conclusion, the POC-CCA assay seems to be a more appropriate tool for S. mansoni diagnosis compared to the Kato-Katz method in endemic communities such as Mwanza Region. Optimization of the tool in terms of cassette-reading could be assessed by computer software which was able to quantify the colour of the lines in the strip of the cassette. |
topic |
Schistosoma mansoni School children CCA Computer image analyses Tanzania |
url |
http://www.sciencedirect.com/science/article/pii/S2405673115300775 |
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