Use of real-time polymerase chain reaction to identify Entamoeba histolytica in schoolchildren from northwest Mexico.

Introduction: Entamoeba histolytica, E. dispar, and E. moshkovskii are morphologically identical, but intestinal amebiasis is caused only by E. histolytica. Mexico is among the countries with high amebae infection rates, although the contribution of pathogenic amoeba to the total detected cases remains unknown, especially in the northwestern dry region. Therefore, the aim of this study was to identify the actual prevalence of E. histolytica using real-time polymerase chain reaction (PCR) in schoolchildren of  northwestern Mexico.

Methodology: Participants were children from five public elementary schools in the low-socioeconomic-level suburban areas of Hermosillo, Sonora, Mexico. One stool sample was collected from each child and analyzed by the Faust technique for Entamoeba spp. and by real-time PCR for E. histolytica.

Results: Analysis of stool  samples from 273 children (9.0 ± 1.5 years of age) resulted in 25 (9.2%) positive for E. histolytica/E. dispar/E. moshkovskii by the Faust technique; of these, 3 were positive for E. histolytica by real-time PCR. In addition, 2 samples that were negative for E. histolytica/E. dispar/E. moshkovskii by the Faust technique were positive by real-time PCR.

Conclusions: The actual prevalence of E. histolytica in our study population was 1.8%, which is lower than those reported in previous studies in other Mexican regions.