title: Overdiagnosis of Entamoeba histolytica and Entamoeba dispar in Nicaragua: a microscopic, triage parasite panel and PCR study.
abstract: BACKGROUND
  Based on stool microscopy, an E. histolytica/E. dispar prevalence of 18.6% was found in León, Nicaragua about 10 years ago. Since then, new non-microscopic methods have been developed to discriminate between pathogenic E. histolytica and nonpathogenic E. dispar. The main objectives of the present study were to evaluate the true prevalence of E. histolytica among individuals with diarrhea and to assess the diagnostic procedures carried out at the health center level.
  
  
  METHODS
  A descriptive study was carried out on patients with diarrhea. Parasite detection was performed by conventional microscopy on native preparations or concentrated and stained specimens, Triage Parasite Panel and by PCR for both E. histolytica and E. dispar.
  
  
  RESULTS
  In 134 individuals with diarrhea, the prevalence of intestinal parasites was 69% as detected by direct stool examination. E. histolytica/E. dispar was found in eight (6%) of the samples, but the health centers reported 24%. In the Triage Parasite Panel only one case of E. histolytica/E. dispar was found. Analysis by PCR showed E. dispar in ten (7.5%) and E. histolytica in two cases (1.5%). The detection of intestinal coccidia and Dientamoeba fragilis required additional staining methods.
  
  
  CONCLUSIONS
  PCR results showed that E. histolytica is a rare finding in patients with diarrhea. At the health centers, E. histolytica, E. histolytica/E. dispar were clearly overdiagnosed, with the consequence of overtreatment.
authors.affiliation: Microbiology and Tumorbiology Center, Karolinska Institute, Stockholm, Sweden. byron.leiva@smi.ki.se
authors.forename: Byron
authors.initials: B
authors.lastname: Leiva
authors.forename: Marianne
authors.initials: M
authors.lastname: Lebbad
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Winiecka-Krusnell
authors.forename: Isabel
authors.initials: I
authors.lastname: Altamirano
authors.forename: Aleyda
authors.initials: A
authors.lastname: Tellez
authors.forename: Ewert
authors.initials: E
authors.lastname: Linder
mesh_terms: D000818:Animals; D003951:Diagnostic Errors; D004747:Entamoeba / Q000166:cytology* / Q000235:genetics* / Q000302:isolation & purification; D004749:Entamoebiasis / Q000175:diagnosis* / Q000469:parasitology*; D006801:Humans; D008853:Microscopy; D009527:Nicaragua; D016133:Polymerase Chain Reaction; D014218:Triage