Clinical significance of high anti-entamoeba histolytica antibody titer in asymptomatic HIV-1-infected individuals

J Infect Dis. 2014 Jun 1;209(11):1801-7. doi: 10.1093/infdis/jit815. Epub 2013 Dec 13.


Background: Anti-Entamoeba histolytica antibody (anti- E. histolytica) is widely used in seroprevalence studies though its clinical significance has not been assessed previously.

Methods: Anti-E. histolytica titer was measured at first visit to our clinic (baseline) in 1303 patients infected with human immunodeficiency virus type 1 (HIV-1). The time to diagnosis of invasive amebiasis was assessed by Kaplan-Meier method and risk factors for the development of invasive amebiasis were assessed by Cox proportional-hazards regression analysis. For patients who developed invasive amebiasis, anti-E. histolytica titers at onset were compared with those at baseline and after treatment.

Results: The anti-E. histolytica seroprevalence in the study population was 21.3% (277/1303). Eighteen patients developed invasive amebiasis during the treatment-free period among 1207 patients who had no history of previous treatment with nitroimidazole. Patients with high anti-E. histolytica titer at baseline developed invasive amebiasis more frequently than those with low anti-E. histolytica titer. Most cases of invasive amebiasis who had high anti-E. histolytica titer at baseline developed within 1 year. High anti-E. histolytica titer was the only independent predictor of future invasive amebiasis. Anti-E. histolytica titer was elevated at the onset of invasive amebiasis in patients with low anti-E. histolytica titer at baseline.

Conclusions: Asymptomatic HIV-1-infected individuals with high anti-E. histolytica titer are at risk of invasive amebiasis probably due to exacerbation of subclinical amebiasis.

Keywords: Entamoeba histolytica; HIV-1; amebiasis; anti-E. histolytica antibody; seroprevalence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Protozoan / blood*
  • Cohort Studies
  • Entamoeba histolytica / immunology*
  • Female
  • HIV Infections / complications*
  • HIV Infections / epidemiology
  • HIV Infections / parasitology
  • HIV-1*
  • Humans
  • Male
  • Middle Aged
  • Retrospective Studies
  • Seroepidemiologic Studies
  • Young Adult


  • Antibodies, Protozoan