Avui, dilluns 8 de juny, el Dipòsit Digital no estarà operatiu de 15:00 a 17:00 h per tasques de manteniment. Disculpeu les molèsties.
Hoy, lunes 8 de junio, el Dipòsit Digital no estará operativo de 15:00 a 17:00 h debido a tareas de mantenimiento. Disculpen las molestias.
Today, Monday, Jun 8th, the Digital Repository will be unavailable due to a system update.

Document type

Article

Version

Published version

Publication date

Publication license

cc by (c) Beltrame et al., 2017
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/113441

Accuracy of parasitological and immunological tests for the screening of human schistosomiasis in immigrants and refugees from African countries: An approach with Latent Class Analysis

Journal Title

Director/Tutor

Journal ISSN

Volume Title

Abstract

BACKGROUND: Schistosomiasis is a neglected infection affecting millions of people, mostly living in sub-Saharan Africa. Morbidity and mortality due to chronic infection are relevant, although schistosomiasis is often clinically silent. Different diagnostic tests have been implemented in order to improve screening and diagnosis, that traditionally rely on parasitological tests with low sensitivity. Aim of this study was to evaluate the accuracy of different tests for the screening of schistosomiasis in African migrants, in a non endemic setting. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective study was conducted on 373 patients screened at the Centre for Tropical Diseases (CTD) in Negrar, Verona, Italy. Biological samples were tested with: stool/urine microscopy, Circulating Cathodic Antigen (CCA) dipstick test, ELISA, Western blot, immune-chromatographic test (ICT). Test accuracy and predictive values of the immunological tests were assessed primarily on the basis of the results of microscopy (primary reference standard): ICT and WB resulted the test with highest sensitivity (94% and 92%, respectively), with a high NPV (98%). CCA showed the highest specificity (93%), but low sensitivity (48%). The analysis was conducted also using a composite reference standard, CRS (patients classified as infected in case of positive microscopy and/or at least 2 concordant positive immunological tests) and Latent Class Analysis (LCA). The latter two models demonstrated excellent agreement (Cohen's kappa: 0.92) for the classification of the results. In fact, they both confirmed ICT as the test with the highest sensitivity (96%) and NPV (97%), moreover PPV was reasonably good (78% and 72% according to CRS and LCA, respectively). ELISA resulted the most specific immunological test (over 99%). The ICT appears to be a suitable screening test, even when used alone. CONCLUSIONS: The rapid test ICT was the most sensitive test, with the potential of being used as a single screening test for African migrants.

Citation

Citation

BELTRAME, Anna, et al. Accuracy of parasitological and immunological tests for the
                screening of human schistosomiasis in immigrants and refugees
                from African countries: An approach with Latent Class Analysis. PLoS Neglected Tropical Diseases. 2017. Vol. 11, num. 6, pags. e0005593. ISSN 1935-2727. [consulted: 9 of June of 2026]. Available at: https://hdl.handle.net/2445/113441

Export metadata

JSON - METS

Share record