Seroepidemiology of Entamoeba histolytica in a slum in northeastern Brazil

Lucia L. Braga, Aldo A.M. Lima, Cynthia L. Sears, Robert D. Newman, Tadesse Wuhib, Clecia A. Paiva, Richard L. Guerrant, Barbara J. Mann

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


Infection with the human pathogenic parasite Entamoeba histolytica has not been well-characterized in northeastern Brazil. In this study, the prevalence of E. histolytica infection in a slum in northeastern Brazil was assayed using an enzyme-linked immunosorbent assay (ELISA) for antibodies against the galactose/N-acetyl-D-galactosamine (Gal/GalNAc)-inhibitable adherence lectin of E. histolytica. Sera from a total of 335 individuals were examined for anti-Gal/GalNAc lectin antibodies. The overall seropositivity was 24.7%; 29.4% of females and 19.4% of males were positive. Among different age groups there was a peak of 40% positivity in the 6-14-year-old age group. There was also familial clustering of seropositivity. To examine colonization, stool samples from 155 people were examined microscopically for the presence of the parasite. Fourteen of 155 stools (9.0%) were identified as containing E. histolytica or nonpathogenic E. dispar. These 14 positive stools were analyzed with an ELISA that detects Gal/GalNAc lectin antigen and can distinguish between E. histolytica and E. dispar. Four stools (29%) were positive for E. histolytica and the remaining 10 were identified as E. dispar-positive. Although the overall colonization rate by microscopy was only 9%, with a third identified as E. histolytica, up to 40% of older children develop serologic evidence of having experienced pathogenic E. histolytica infection. The results of this study demonstrate that this community in northeastern Brazil is highly endemic for E. histolytica with infection rates similar to other developing nations.

Original languageEnglish (US)
Pages (from-to)693-697
Number of pages5
JournalAmerican Journal of Tropical Medicine and Hygiene
Issue number6
StatePublished - Dec 1996

ASJC Scopus subject areas

  • Parasitology
  • Virology
  • Infectious Diseases


Dive into the research topics of 'Seroepidemiology of Entamoeba histolytica in a slum in northeastern Brazil'. Together they form a unique fingerprint.

Cite this