title: Increased detection of schistosomiasis with Kato-Katz and SWAP-IgG-ELISA in a Northeastern Brazil low-intensity transmission area.
abstract: BACKGROUND
  The laboratory diagnosis of schistosomiasis is based mainly on the detection of parasite eggs in stool samples through the Kato-Katz (KK) technique, reading one slide by test. However, a widely known limitation of parasitological methods is reduced sensitivity, particularly in low endemic areas.
  
  
  METHODS
  To increase sensitivity, we conducted further slide readings from the same stool sample using the parasitological method associated with a serological test. We used the KK method (three slides) and the IgG anti-Schistosoma mansoni-enzyme-linked immunosorbent assay (ELISA) technique to diagnose schistosomiasis in low endemic areas in the Brazilian State of Ceará. Fecal samples and sera from 250 individuals were analyzed.
  
  
  RESULTS
  Sixteen percent and 47.2% of samples were positive in parasitological tests and serological tests, respectively. Parasitological methods showed that 32 (80%) individuals tested positive on the first slide, 6 (15%) on the second slide, and 2 (5%) on the third. The performance of the ELISA test in the diagnosis, using the KK method as diagnostic reference, showed a negative predictive value of 100%, with specificity and positive predictive values of 62.8% and 33.9%, respectively.
  
  
  CONCLUSIONS
  In this study, the increase from one to three slides analyzed per sample using the KK technique was shown to be a useful procedure for increasing the diagnostic sensitivity of this technique.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Odontologia e Enfermagem, Universidade Federal do Ceará, Fortaleza, CE, Brasil.
authors.forename: Teiliane Rodrigues
authors.initials: TR
authors.lastname: Carneiro
authors.forename: Marta Cristhiany Cunha
authors.initials: MC
authors.lastname: Pinheiro
authors.forename: Sara Menezes
authors.initials: SM
authors.lastname: de Oliveira
authors.forename: Ana Lúcia de Paula
authors.initials: AL
authors.lastname: Hanemann
authors.forename: José Ajax Nogueira
authors.initials: JA
authors.lastname: Queiroz
authors.forename: Fernando Schemelzer Moraes
authors.initials: FS
authors.lastname: Bezerra
mesh_terms: D000328:Adult; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood*; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005243:Feces / Q000469:parasitology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D010270:Parasite Egg Count / Q000379:methods; D012550:Schistosoma mansoni / Q000276:immunology / Q000302:isolation & purification*; D012555:Schistosomiasis mansoni / Q000175:diagnosis* / Q000453:epidemiology; D012680:Sensitivity and Specificity
chemical_list: D000909:Antibodies, Helminth; D007074:Immunoglobulin G