Sara Roose, Marco Prato, Adama Kazienga, Iris Peelaers, Justien Arens, Gemechu Tadessa Leta, Cristina Mazzi, Dora Buonfrate, Bruno Levecke, Francesca Tamarozzi
{"title":"Technical evaluation of the InBios Strongy Detect IgG ELISA assay for the diagnosis of Strongyloides stercoralis infection.","authors":"Sara Roose, Marco Prato, Adama Kazienga, Iris Peelaers, Justien Arens, Gemechu Tadessa Leta, Cristina Mazzi, Dora Buonfrate, Bruno Levecke, Francesca Tamarozzi","doi":"10.1186/s13071-024-06501-4","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Strongyloidiasis is a neglected tropical disease (NTD) caused by the soil-transmitted helminth Strongyloides stercoralis, recently included in the 2030 targets of the World Health Organization for the control of STHs. Assessment of infection prevalence is fundamental for decision-making about the implementation of control programs, but diagnostic assays to be applied in such context require evaluation. Seroassays based on recombinant antigens, which could be produced in a standardized and scalable manner, are particularly appealing for use in control programs. In this study, we performed a technical evaluation of the InBios Strongy Detect IgG ELISA, based on recombinant antigens NIE and SsIR, which has shown promising for field use.</p><p><strong>Methods: </strong>A total of 46 plasma samples from Ethiopian children were used for this technical evaluation. Repeatability was evaluated on duplicate samples per plate, on four plates per day for 3 days using Bland-Altman plots, analysis of residuals, and variance components analysis. Three samples were selected for evaluation of the uniformity of test results within a single plate (border effect) by two-sided t-test. Correlation between samples and internal ELISA positive controls was analyzed using Spearman's rank correlation coefficient applied on the results of 777 samples analyzed with the assay in a previous field-based study.</p><p><strong>Results: </strong>Within and between plate residuals ranged from -0.05 to + 0.05 and -0.1 to + 0.1, respectively. Total variance was estimated at 0.327; 99.6% of variation could be attributed to the samples. There was no systematic border effect and a negligible correlation between positive internal control and samples results (R<sup>2</sup> = 0.213; p < 0.001).</p><p><strong>Conclusion: </strong>The results obtained in this study, in highly controlled conditions, point toward the InBios Strongy Detect IgG ELISA assay being reproducible, with no systematic border effect. These results encourage further assay's development and evaluation for use in practice, including determination of preset cutoff values for positivity, which is currently not provided.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"534"},"PeriodicalIF":3.0000,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Parasites & Vectors","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1186/s13071-024-06501-4","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PARASITOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Strongyloidiasis is a neglected tropical disease (NTD) caused by the soil-transmitted helminth Strongyloides stercoralis, recently included in the 2030 targets of the World Health Organization for the control of STHs. Assessment of infection prevalence is fundamental for decision-making about the implementation of control programs, but diagnostic assays to be applied in such context require evaluation. Seroassays based on recombinant antigens, which could be produced in a standardized and scalable manner, are particularly appealing for use in control programs. In this study, we performed a technical evaluation of the InBios Strongy Detect IgG ELISA, based on recombinant antigens NIE and SsIR, which has shown promising for field use.
Methods: A total of 46 plasma samples from Ethiopian children were used for this technical evaluation. Repeatability was evaluated on duplicate samples per plate, on four plates per day for 3 days using Bland-Altman plots, analysis of residuals, and variance components analysis. Three samples were selected for evaluation of the uniformity of test results within a single plate (border effect) by two-sided t-test. Correlation between samples and internal ELISA positive controls was analyzed using Spearman's rank correlation coefficient applied on the results of 777 samples analyzed with the assay in a previous field-based study.
Results: Within and between plate residuals ranged from -0.05 to + 0.05 and -0.1 to + 0.1, respectively. Total variance was estimated at 0.327; 99.6% of variation could be attributed to the samples. There was no systematic border effect and a negligible correlation between positive internal control and samples results (R2 = 0.213; p < 0.001).
Conclusion: The results obtained in this study, in highly controlled conditions, point toward the InBios Strongy Detect IgG ELISA assay being reproducible, with no systematic border effect. These results encourage further assay's development and evaluation for use in practice, including determination of preset cutoff values for positivity, which is currently not provided.
期刊介绍:
Parasites & Vectors is an open access, peer-reviewed online journal dealing with the biology of parasites, parasitic diseases, intermediate hosts, vectors and vector-borne pathogens. Manuscripts published in this journal will be available to all worldwide, with no barriers to access, immediately following acceptance. However, authors retain the copyright of their material and may use it, or distribute it, as they wish.
Manuscripts on all aspects of the basic and applied biology of parasites, intermediate hosts, vectors and vector-borne pathogens will be considered. In addition to the traditional and well-established areas of science in these fields, we also aim to provide a vehicle for publication of the rapidly developing resources and technology in parasite, intermediate host and vector genomics and their impacts on biological research. We are able to publish large datasets and extensive results, frequently associated with genomic and post-genomic technologies, which are not readily accommodated in traditional journals. Manuscripts addressing broader issues, for example economics, social sciences and global climate change in relation to parasites, vectors and disease control, are also welcomed.