PLoS Neglected Tropical Diseases
Volume 11, Issue 6, 2017

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 (Article) (Open Access)

Beltrame A. , Guerriero M. , Angheben A. , Gobbi F. , Requena-Mendez A. , Zammarchi L. , Formenti F. , Perandin F. , Buonfrate D.* , Bisoffi Z.
  • a Centre for Tropical Diseases, Ospedale Sacro Cuore Don Calabria, Negrar, Verona, Italy
  • b University of Verona, Department of Computer Science, Verona, Italy
  • c Centre for Tropical Diseases, Ospedale Sacro Cuore Don Calabria, Negrar, Verona, Italy
  • d Centre for Tropical Diseases, Ospedale Sacro Cuore Don Calabria, Negrar, Verona, Italy
  • e Barcelona Institute for Global Health, ISGlobal-CRESIB, Universitat de Barcelona, Barcelona, Spain
  • f Infectious and Tropical Diseases Department, Azienda Ospedaliera Universitaria Careggi, Florence, Italy
  • g Centre for Tropical Diseases, Ospedale Sacro Cuore Don Calabria, Negrar, Verona, Italy
  • h Centre for Tropical Diseases, Ospedale Sacro Cuore Don Calabria, Negrar, Verona, Italy
  • i Centre for Tropical Diseases, Ospedale Sacro Cuore Don Calabria, Negrar, Verona, Italy
  • j Centre for Tropical Diseases, Ospedale Sacro Cuore Don Calabria, Negrar, Verona, Italy

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. © 2017 Beltrame et al.

Author Keywords

[No Keywords available]

Index Keywords

immigrant Africa south of the Sahara refugee mass screening economics predictive value clinical effectiveness human Refugees Glycoproteins Helminth Proteins feces analysis diagnostic accuracy urine CCA protein, Schistosoma mansoni helminth protein Immunochromatography glycoprotein nonhuman procedures Young Adult health care cost Humans migrant male Emigrants and Immigrants female enzyme linked immunosorbent assay Africa hematuria antigen detection immunoaffinity chromatography sensitivity and specificity Article Retrospective Studies Antigens, Helminth parasite antigen major clinical study adult schistosomiasis microscopy Urinalysis retrospective study Western blotting Enzyme-Linked Immunosorbent Assay Child
Link
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021371337&doi=10.1371%2fjournal.pntd.0005593&partnerID=40&md5=1c59890dce1a5dfda53d278a9b764646
DOI: 10.1371/journal.pntd.0005593
ISSN: 19352727
Cited by: 21
Original Language: English