Prevalence of Entamoeba histolytica and Entamoeba dispar among residents of an urban slum area in Manila, Philippines as detected by the polymerase chain reaction.

This study aimed to determine the prevalence of Entamoeba histolytica and Entamoeba dispar infections among residents in BASECO compound, Manila, Philippines using polymerase chain reaction (PCR). Formalin-ether concentration technique (FECT)-treated stool samples were examined under the light microscope to determine the presence of Entamoeba, helminths and other protozoan parasites. DNA was directly extracted from the FECT-treated samples and was subjected to PCR to determine E. histolytica and E. dispar infections. In this study, stool samples were collected from 2,232 residents of BASECO compound. Microscopic examination of FECT concentrated samples found 38 samples (1.703%) positive for E. histolytica/E. dispar. The E. histolytica/E. dispar microscopically positive samples were further analyzed by PCR and found 8 samples (0.358%) infected with E. histolytica and 23 samples (1.030%) infected with E. dispar. No statistically significant difference was observed in the sex distribution, while statistically significant difference was observed among the age group and area distribution of both the Entamoeba species. The results demonstrate PCR using DNA extracted from the formalin-fixed stools as an effective epidemiologic detection method of E. histolytica and E. dispar infections.