Entamoeba histolytica infections in a slum community in Manila, Philippines as detected by stool ELISA.

This study aimed to determine the prevalence of Entamoeba histolytica in BASECO, an urban slum community situated in Manila Harbor, Manila, Philippines using stool enzyme-linked immunosorbent assay (ELISA). It also aimed to determine if age, sex, and geographic location are contributory factors to the prevalence of E. histolytica. Stool samples were collected from 627 urban slum community residents of BASECO. Samples were viewed under light microscopy and the different parasites observed were identified. Stool ELISA was done using E. histolytica II antigen detection kits (TECHLAB®). Using E. histolytica II kits, E. histolytica had a prevalence of 9.09% (5/55) among the microscopically-positive samples for E. histolytica/E. dispar indicating a greater prevalence for the nonpathogenic species. No significant difference was observed in the prevalence of infection across all three variables: age, sex and geographic location. The overall prevalence of E. histolytica in BASECO, Manila, Philippines is 0.797% (5/627) which is lower than previous studies done on estimating the prevalence of E. histolytica using various techniques.

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.

Subtype analysis of Blastocystis sp. isolates from human and canine hosts in an urban community in the Philippines.

Blastocystis sp. is a common gut-dwelling protist of both humans and animals. A cross-sectional survey among humans and their dogs was conducted to determine the prevalence of Blastocystis infection and to characterize the subtype (ST) distribution in an urban community in the Philippines. Fecal specimens from 1,271 humans and 145 dogs were collected and inoculated in diphasic culture medium. Prevalence of Blastocystis by culture was 13.0% (95% CI = 11.2-15.0) and 14.5% (95% CI = 9.6-21.2) for humans and dogs, respectively. A total of 168 culture isolates were genotyped using polymerase chain reaction (PCR) with seven pairs of ST-specific sequence-tagged-site (STS) primers. In humans, the ST present in this study were ST1 with 22.6% (95% CI = 17.2-29.0), ST2 with 3.1% (95% CI = 1.3-6.7), ST3 with 41.4% (95% CI= 34.9-48.6), ST4 with 14.8% (95% CI = 10.5-20.6), ST5 with 4.1% (95% CI = 2.0-8.0), and unknown ST with 13.9% (95% CI = 9.6-19.4). In dogs, the ST present in this study were ST1 with 4.3% (95% CI = 0.0-29.0), ST2 with 8.7% (95% CI = 1.3-28.0), ST3 with 17.4% (95% CI = 6.4-37.7), ST4 with 13.0% (95% CI = 3.7-33.0), ST5 with 13.0% (95% CI = 3.7-33.0), and unknown ST with 47.8% (95% CI = 29.2-67.0). This is the first study that reported Blastocystis ST4 in human and canine hosts in the Philippines.

Epidemiologic Study of Blastocystis Infection in an Urban Community in the Philippines.

Blastocystis has been considered as the most common intestinal parasite in humans and has an augmented impact on public health. However, the prevalence of this parasite in the Philippines has not been determined. To contribute to a better understanding of the epidemiology of this infection, a cross-sectional study aimed at providing the first documented data on the prevalence and correlates, sociodemographic factors, hygiene practices, source of water supply, and dog ownership, associated with Blastocystis infection was carried out in randomly selected communities at Pateros, Metro Manila. Fecal samples from respondents were collected and cultured in diphasic agar medium for 3-7 days and examined using light microscopy. Of the 1,271 respondents, 12.98% (95% CI: 11.13-14.83) were detected positive for Blastocystis. Among the correlates of Blastocystis infection, dog ownership was found significantly associated as confirmed by multivariate analysis. Therefore, this factor should be considered in information to create awareness about Blastocystis and to prevent and control Blastocystis infection in particular and diarrheal diseases in general. Further studies using molecular approaches to distinguish subtype and to determine genetic characteristics of isolates from humans and dogs are recommended to analyze their relationship and provide more conclusive evidence of cross-transmission.