title: [Concordance between the zinc sulphate flotation and centrifugal sedimentation methods for the diagnosis of intestinal parasites].
abstract: BACKGROUND
  The diagnosis of intestinal parasitic infections depends on the parasite load, the specific gravity density of the parasite eggs, oocysts or cysts, and the density and viscosity of flotation or sedimentation medium where faeces are processed.
  
  
  OBJECTIVE
  To evaluate the concordance between zinc sulphate flotation and centrifugal sedimentation in the recovery of parasites in faecal samples of children.
  
  
  METHODS
  Faecal samples of 330 children from day care centers were evaluated by zinc sulphate flotation and centrifugal sedimentation techniques. The frequencies of detection of parasites by each method were determined and the agreement between the diagnostic techniques was evaluated using the kappa index, with 95% confidence intervals.
  
  
  RESULTS
  The faecal flotation in zinc sulphate diagnosed significantly more cases of Trichuris trichiura infection when compared to centrifugal sedimentation (39/330; 11.8% vs. 13/330; 3.9%, p<0.001), with low diagnostic concordance between methods (kappa=0.264; 95% CI: 0.102-0.427). Moreover, all positive samples for Enterobius vermicularis eggs (n=5) and Strongyloides stercoralis larvae (n=3) were diagnosed only by zinc sulphate. No statistical differences were observed between methods for protozoa identification.
  
  
  CONCLUSIONS
  The results showed that centrifugal flotation in zinc sulphate solution was significantly more likely to detect light helminths eggs such as those of T. trichiura and E. vermicularis in faeces than the centrifugal sedimentation process.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal da Bahia, Bahia, Brasil. biomedica@ins.gov.co.
authors.forename: Elizabete De Jesus
authors.initials: EJ
authors.lastname: Inês
authors.forename: Flavia Thamiris Figueiredo
authors.initials: FT
authors.lastname: Pacheco
authors.forename: Milena Carneiro
authors.initials: MC
authors.lastname: Pinto
authors.forename: Patrícia Silva de Almeida
authors.initials: PS
authors.lastname: Mendes
authors.forename: Hugo
authors.initials: H
authors.lastname: Da Costa-Ribeiro
authors.forename: Neci Matos
authors.initials: NM
authors.lastname: Soares
authors.forename: Márcia Cristina Aquino
authors.initials: MC
authors.lastname: Teixeira
mesh_terms: D000818:Animals; D002498:Centrifugation; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D005243:Feces / Q000469:parasitology*; D005260:Female; D006373:Helminthiasis / Q000175:diagnosis / Q000469:parasitology; D006376:Helminths / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007411:Intestinal Diseases, Parasitic / Q000175:diagnosis* / Q000469:parasitology; D008297:Male; D010063:Ovum; D010270:Parasite Egg Count / Q000379:methods*; D010271:Parasites / Q000302:isolation & purification*; D010274:Parasitology / Q000379:methods*; D011528:Protozoan Infections / Q000175:diagnosis / Q000469:parasitology; D019287:Zinc Sulfate
chemical_list: D019287:Zinc Sulfate
keywords: Intestinal parasites/diagnosis; child; flotation; sedimentation