title: Diagnostic accuracy of five serologic tests for Strongyloides stercoralis infection.
abstract: BACKGROUND
  The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based reference ("gold") standard.
  
  
  METHODS
  The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the primary reference standard, but also using a composite reference standard (based on a combination of tests).
  
  
  RESULTS
  According to the latter standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2-96.9), followed by IVD-ELISA (92.3%, 87.7-96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9-100), followed by IVD-ELISA (97.4%, 95.5-99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIE-LIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains ≥70% sensitivity.
  
  
  CONCLUSIONS
  NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.
authors.affiliation: Center for Tropical Diseases (CTD), Sacro Cuore Hospital, Negrar, Verona, Italy ; Coordinating Resources to Assess and Improve Health Status of Migrants from Latin America (COHEMI) Project Study Group, European Commission, Health Cooperation Work Programme, FP7 (GA-261495).
authors.forename: Zeno
authors.initials: Z
authors.lastname: Bisoffi
authors.affiliation: Center for Tropical Diseases (CTD), Sacro Cuore Hospital, Negrar, Verona, Italy ; Coordinating Resources to Assess and Improve Health Status of Migrants from Latin America (COHEMI) Project Study Group, European Commission, Health Cooperation Work Programme, FP7 (GA-261495).
authors.forename: Dora
authors.initials: D
authors.lastname: Buonfrate
authors.affiliation: Department of Public Health, IRCCS - Mario Negri Institute for Pharmacological Research, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Sequi
authors.affiliation: National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America.
authors.forename: Rojelio
authors.initials: R
authors.lastname: Mejia
authors.affiliation: Instituto de Investigaciones en Enfermedades Tropicales - Universidad Nacional de Salta/CONICET, Oran, Argentina.
authors.forename: Ruben O
authors.initials: RO
authors.lastname: Cimino
authors.affiliation: Instituto de Investigaciones en Enfermedades Tropicales - Universidad Nacional de Salta/CONICET, Oran, Argentina.
authors.forename: Alejandro J
authors.initials: AJ
authors.lastname: Krolewiecki
authors.affiliation: Center for Tropical Diseases (CTD), Sacro Cuore Hospital, Negrar, Verona, Italy ; Coordinating Resources to Assess and Improve Health Status of Migrants from Latin America (COHEMI) Project Study Group, European Commission, Health Cooperation Work Programme, FP7 (GA-261495).
authors.forename: Marco
authors.initials: M
authors.lastname: Albonico
authors.affiliation: Center for Tropical Diseases (CTD), Sacro Cuore Hospital, Negrar, Verona, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Gobbo
authors.affiliation: Center for Tropical Diseases (CTD), Sacro Cuore Hospital, Negrar, Verona, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Bonafini
authors.affiliation: Center for Tropical Diseases (CTD), Sacro Cuore Hospital, Negrar, Verona, Italy ; Coordinating Resources to Assess and Improve Health Status of Migrants from Latin America (COHEMI) Project Study Group, European Commission, Health Cooperation Work Programme, FP7 (GA-261495).
authors.forename: Andrea
authors.initials: A
authors.lastname: Angheben
authors.affiliation: Coordinating Resources to Assess and Improve Health Status of Migrants from Latin America (COHEMI) Project Study Group, European Commission, Health Cooperation Work Programme, FP7 (GA-261495) ; Barcelona Centre for International Health Research (CRESIB, Hospital Clinic-Universitat de Barcelona), Barcelona, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Requena-Mendez
authors.affiliation: Coordinating Resources to Assess and Improve Health Status of Migrants from Latin America (COHEMI) Project Study Group, European Commission, Health Cooperation Work Programme, FP7 (GA-261495) ; Barcelona Centre for International Health Research (CRESIB, Hospital Clinic-Universitat de Barcelona), Barcelona, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Muñoz
authors.affiliation: National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Nutman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010274:Parasitology / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D017171:Strongyloides stercoralis / Q000276:immunology*; D013322:Strongyloidiasis / Q000175:diagnosis*; D055815:Young Adult