Inactivation of Giardia intestinalis cysts in water using a sonochemical method based on mid-high-frequency waves.

Giardia intestinalis is a pollutant of food and water, resistant to conventional disinfection treatments and its elimination requires effective methods action. Herein, mid-high-frequency ultrasound (375 kHz), which produces HO• and H2O2, was used as an alternative method of treatment to inactivate Giardia intestinalis cysts in water. The effect of ultrasound power (4.0, 11.2, 24.4 W) on the sonogeneration of radicals was tested, showing that 24.4 W was the condition most favorable to treat the parasite. The viability of the protozoan cysts was evaluated using the immunofluorescence technique and vital stains, showing this protocol was useful to quantify the parasite. The sonochemical method (at 375 kHz and 24.4 W) was applied at different treatment times (10, 20, and 40 min). A significant decrease in the protozoan concentration (reduction of 52.4% of viable cysts) was observed after 20 min of treatment. However, the extension of treatment time up to 40 min did not increase the inactivation. Disinfecting action was associated with attacks on the Giardia intestinalis cyst by sonogenerated HO• and H2O2 (which may induce structural damage, even the cell lysis). For future work is recommended to test combinations with UVC or Fenton process to enhance the inactivating action of this method.•Mid-high-frequency ultrasound produces HO• and H2O2 profitable to inactivate Giardia intestinalis.•Immunofluorescence technique and vital stains allowed us to quantify the parasite viability.•Giardia intestinalis cysts concentration decreased by 52.4% after only 20 min of sonication.

Multilocus Sequence Typing helps understand the genetic diversity of Cryptosporidium hominis and Cryptosporidium parvum isolated from Colombian patients.

Multilocus Sequence Typing has become a useful tool for the study of the genetic diversity and population structure of different organisms. In this study, a MLST approach with seven loci (CP47, MS5, MS9, MSC6-7, TP14, and gp60) was used to analyze the genetic diversity of Cryptosporidium hominis and Cryptosporidium parvum isolated from 28 Colombian patients. Five Cryptosporidium species were identified: C. hominis, C. parvum, Cryptosporidium felis, Cryptosporidium meleagridis, and Cryptosporidium suis. Unilocus gp60 analysis identified four allelic families for C. hominis (Ia, Ib, Id, and Ie) and two for C. parvum (IIa and IIc). There was polymorphic behavior of all markers evaluated for both C. hominis and C. parvum, particularly with the CP47, MS5, and gp60 markers. Phylogenetic analysis with consensus sequences (CS) of the markers showed a taxonomic agreement with the results obtained with the 18S rRNA and gp60 gene. Additionally, two monophyletic clades that clustered the species C. hominis and C. parvum were detected, with a higher number of subclades within the monophyletic groups compared to those with the gp60 gene. Thirteen MLG were identified for C. hominis and eight for C. parvum. Haplotypic and nucleotide diversity were detected, but only the latter was affected by the gp60 exclusion from the CS analysis. The gene fixation index showed an evolutionary closeness between the C. hominis samples and a less evolutionary closeness and greater sequence divergence in the C. parvum samples. Data obtained in this work support the implementation of MLST analysis in the study of the genetic diversity of Cryptosporidium, considering the more detailed information that it provides, which may explain some genetic events that with an unilocus approach could not be established. This is the first multilocus analysis of the intra-specific variability of Cryptosporidium from humans in South America.

Cryptosporidium hominis Phylogenomic Analysis Reveals Separate Lineages With Continental Segregation.

Cryptosporidium is a leading cause of waterborne outbreaks globally, and Cryptosporidium hominis and C. parvum are the principal cause of human cryptosporidiosis on the planet. Thanks to the advances in Next-Generation Sequencing (NGS) sequencing and bioinformatic software development, more than 100 genomes have been generated in the last decade using a metagenomic-like strategy. This procedure involves the parasite oocyst enrichment from stool samples of infected individuals, NGS sequencing, metagenomic assembly, parasite genome computational filtering, and comparative genomic analysis. Following this approach, genomes of infected individuals of all continents have been generated, although with striking different quality results. In this study, we performed a thorough comparison, in terms of assembly quality and purity, of 100+ de novo assembled genomes of C. hominis. Remarkably, after quality genome filtering, a comprehensive phylogenomic analysis allowed us to discover that C. hominis encompasses two lineages with continental segregation. These lineages were named based on the observed continental distribution bias as C. hominis Euro-American (EA) and the C. hominis Afro-Asian (AA) lineages.

Prevalence of intestinal parasites in a cohort of HIVinfected patients from Antioquia, Colombia. / Prevalencia de parásitos intestinales en una cohorte de pacientes positivos para HIV en Antioquia, Colombia

INTRODUCTION: HIV infection is still a public health problem worldwide and co-infections with other infectious agents including intestinal parasites are of particular concern, mainly in developing countries like Colombia. OBJECTIVE: To conduct a cross-sectional study in patients attending an HIV care program in Antioquia given that there have been few intestinal parasites prevalence studies among the HIV population in the country. MATERIAL AND METHODS: We evaluated stool samples from 192 patients by direct wet mount and concentration, modified Ziehl Neelsen staining, and agar plate culture. Univariate and correlation analyses were done to explore the association between socio-demographic and clinical characteristics and parasitological data. RESULTS: The overall prevalence of intestinal parasites in HIV-positive subjects was 29.2% (56/192; 95% CI: 22.8% - 35.6%). Entamoeba histolytica/dispar/moshkosvkii with 13.0% (25/192; 95% CI: 8.2% - 17.8%) and Blastocystis with 12.0% (23/192; 95% CI: 7.4% - 16.6%) were the most frequent. Opportunistic parasites like Cryptosporidium spp. and Cystoisospora belli were less prevalent, each one with 0.5% of positive samples (1/192; 95% CI: 0.1% - 1.5%). Commensal protozoa were also detected with a prevalence of 18.8% (36/192; 95% CI: 13.3% - 24.3%). Most of the individuals in the study had a controlled viral load and an LTCD4 count greater than 200 cel/µL. A small percentage (9.3%) had diarrhea. Bivariate analysis and multivariate logistic regression showed that only age and having pets had a significant association with intestinal parasites in this cohort. CONCLUSIONS: Our results confirmed that the evaluated population is at high risk of intestinal parasite infection, which highlights the need for routine screening of gastrointestinal parasites to provide prompt treatment and reduce possible complications.

Introducción. La infección por HIV y las coinfecciones con otros agentes infecciosos, incluidos los parásitos intestinales, son motivo de especial preocupación en países en desarrollo como Colombia. Objetivo. Hacer un estudio transversal en pacientes que asisten a un programa de atención de HIV en el departamento de Antioquia, dado que los estudios de prevalencia de parásitos intestinales en la población con HIV son escasos en el país. Materiales y métodos. Se evaluaron 192 muestras de materia fecal mediante examen coprológico directo y por concentración, tinción de Ziehl-Neelsen modificada, y aislamiento en agar. Se hicieron análisis univariados y de correlación, para explorar la asociación entre las características sociodemográficas y clínicas, y los datos parasitológicos. Resultados. La prevalencia global de parásitos intestinales en pacientes positivos para VIH fue del 29.2 % (56/192; IC95% 22.8-35.6 %), siendo Entamoeba histolytica/dispar/moshkosvkii, con 13.0 % (25/192; IC95% 8.2-17.8 %), y Blastocystis, con 12.0 % (23/192; IC95% 7.4-16.6 %), los mas frecuentes. Los parásitos oportunistas Cryptosporidium spp. y Cystoisospora belli fueron menos prevalentes, cada uno con 0.5 % (1/192; IC95% 0.1-1.5 %) de muestras positivas. También, se detectaron protozoos comensales, con una prevalencia del 18,8 % (36/192; IC95% 13,3-24,3 %). La mayoría de los individuos tenía una carga viral controlada y un recuento de linfocitos T CD4 superior a 200 células/µl. Un pequeño porcentaje (9,3 %) presentó diarrea. La edad y el tener mascotas mostraron una asociación significativa con la presencia de parásitos intestinales. Conclusión. Se confirmó que la población evaluada tiene un alto riesgo de infección por parásitos intestinales, lo que resalta la necesidad de un protocolo de diagnóstico para el cribado de dichos agentes, con el fin de brindar un tratamiento rápido y reducir las posibles complicaciones.

Prevalence of intestinal parasites in a cohort of HIV- infected patients from Antioquia, Colombia / Prevalencia de parásitos intestinales en una cohorte de pacientes positivos para HIV en Antioquia, Colombia

Abstract | Introduction: HIV infection is still a public health problem worldwide and co-infections with other infectious agents including intestinal parasites are of particular concern, mainly in developing countries like Colombia. Objective: To conduct a cross-sectional study in patients attending an HIV care program in Antioquia given that there have been few intestinal parasites prevalence studies among the HIV population in the country. Material and methods: We evaluated stool samples from 192 patients by direct wet mount and concentration, modified Ziehl Neelsen staining, and agar plate culture. Univariate and correlation analyses were done to explore the association between socio-demographic and clinical characteristics and parasitological data. Results: The overall prevalence of intestinal parasites in HIV-positive subjects was 29.2% (56/192; 95% CI: 22.8% - 35.6%). Entamoeba histolytica/dispar/moshkosvkii with 13.0% (25/192; 95% CI: 8.2% - 17.8%) and Blastocystis with 12.0% (23/192; 95% CI: 7.4% -16.6%) were the most frequent. Opportunistic parasites like Cryptosporidium spp. and Cystoisospora belli were less prevalent, each one with 0.5% of positive samples (1/192; 95% CI: 0.1% - 1.5%). Commensal protozoa were also detected with a prevalence of 18.8% (36/192; 95% CI: 13.3% - 24.3%). Most of the individuals in the study had a controlled viral load and an LTCD4 count greater than 200 cel/µL. A small percentage (9.3%) had diarrhea. Bivariate analysis and multivariate logistic regression showed that only age and having pets had a significant association with intestinal parasites in this cohort. Conclusions: Our results confirmed that the evaluated population is at high risk of intestinal parasite infection, which highlights the need for routine screening of gastrointestinal parasites to provide prompt treatment and reduce possible complications.

Resumen | Introducción. La infección por HIV y las coinfecciones con otros agentes infecciosos, incluidos los parásitos intestinales, son motivo de especial preocupación en países en desarrollo como Colombia. Objetivo. Hacer un estudio transversal en pacientes que asisten a un programa de atención de HIV en el departamento de Antioquia, dado que los estudios de prevalencia de parásitos intestinales en la población con HIV son escasos en el país. Materiales y métodos. Se evaluaron 192 muestras de materia fecal mediante examen coprológico directo y por concentración, tinción de Ziehl-Neelsen modificada, y aislamiento en agar. Se hicieron análisis univariados y de correlación, para explorar la asociación entre las características sociodemográficas y clínicas, y los datos parasitológicos. Resultados. La prevalencia global de parásitos intestinales en pacientes positivos para VIH fue del 29.2 % (56/192; IC95% 22.8-35.6 %), siendo Entamoeba histolytica/dispar/moshkosvkii, con 13.0 % (25/192; IC95% 8.2-17.8 %), y Blastocystis, con 12.0 % (23/192; IC95% 7.4-16.6 %), los mas frecuentes. Los parásitos oportunistas Cryptosporidium spp. Y Cystoisospora belli fueron menos prevalentes, cada uno con 0.5 % (1/192; IC95% 0.1-1.5 %) de muestras positivas. También, se detectaron protozoos comensales, con una prevalencia del 18,8 % (36/192; IC95% 13,3-24,3 %). La mayoría de los individuos tenía una carga viral controlada y un recuento de linfocitos T CD4 superior a 200 células/μl. Un pequeño porcentaje (9,3 %) presentó diarrea. La edad y el tener mascotas mostraron una asociación significativa con la presencia de parásitos intestinales. Conclusión. Se confirmó que la población evaluada tiene un alto riesgo de infección por parásitos intestinales, lo que resalta la necesidad de un protocolo de diagnóstico para el cribado de dichos agentes, con el fin de brindar un tratamiento rápido y reducir las posibles complicaciones.

Chronic Cystoisospora belli infection in a Colombian patient living with HIV and poor adherence to highly active antiretroviral therapy. / Infección crónica por Cystoisospora belli en un paciente colombiano con HIV y cumplimiento deficiente de la terapia antirretroviral de gran actividad

Cystoisospora belli is an intestinal Apicomplexan parasite associated with diarrheal illness and disseminated infections in humans, mainly immunocompromised individuals such as those living with the human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS). An irregular administration of highly active antiretroviral therapy (HAART) in HIV patients may increase the risk of opportunistic infections like cystoisosporiasis. We describe here a case of C. belli infection in a Colombian HIV patient with chronic gastrointestinal syndrome and poor adherence to HAART. His clinical and parasitological cure was achieved with trimethoprim-sulfamethoxazole treatment. Although a reduction in the number of C. belli cases has been observed since the use of HAART, this parasite still has to be considered as a differential diagnosis of diarrheal disease in HIV/AIDS patients. Effective interventions enhancing adherence to HAART should be included in HIV patient care programs.

Cystoisospora belli es un parásito intestinal del filo Apicomplexa asociado con enfermedades diarreicas e infecciones diseminadas en humanos, principalmente en individuos inmunocomprometidos, como aquellos infectados con el virus de la inmunodeficiencia humana (HIV) o el síndrome de inmunodeficiencia adquirida (sida). El cumplimiento inadecuado de la terapia antirretroviral de gran actividad (TARGA) puede aumentar el riego de infecciones oportunistas, incluida la cistoisosporiasis. Se describe el caso de infección por C. belli en un paciente colombiano con HIV, que presentó un síndrome gastrointestinal crónico e incumplía el tratamiento con la TARGA. Después del diagnóstico parasitológico, el paciente fue tratado con trimetoprimsulfametoxazol, lográndose la recuperación clínica y la cura parasitológica. Aunque se ha observado una reducción en el número de casos de C. belli desde la implementación de la TARGA, este parásito aún debe considerarse en el diagnóstico diferencial de las enfermedades diarreicas en pacientes con HIV/sida. Los programas de atención deben incluir intervenciones efectivas que potencien el cumplimiento de la TARGA en estos pacientes.

Chronic Cystoisospora belli infection in a Colombian patient living with HIV and poor adherence to highly active antiretroviral therapy / Infección crónica por Cystoisospora belli en un paciente colombiano con HIV y cumplimiento deficiente de la terapia antirretroviral de gran actividad

Abstract | Cystoisospora belli is an intestinal Apicomplexan parasite associated with diarrheal illness and disseminated infections in humans, mainly immunocompromised individuals such as those living with the human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS). An irregular administration of highly active antiretroviral therapy (HAART) in HIV patients may increase the risk of opportunistic infections like cystoisosporiasis. We describe here a case of C. belli infection in a Colombian HIV patient with chronic gastrointestinal syndrome and poor adherence to HAART. His clinical and parasitological cure was achieved with trimethoprim-sulfamethoxazole treatment. Although a reduction in the number of C. belli cases has been observed since the use of HAART, this parasite still has to be considered as a differential diagnosis of diarrheal disease in HIV/AIDS patients. Effective interventions enhancing adherence to HAART should be included in HIV patient care programs.

Resumen | Cystoisospora belli es un parásito intestinal del filo Apicomplexa asociado con enfermedades diarreicas e infecciones diseminadas en humanos, principalmente en individuos inmunocomprometidos, como aquellos infectados con el virus de la inmunodeficiencia humana (HIV) o el síndrome de inmunodeficiencia adquirida (sida). El cumplimiento inadecuado de la terapia antirretroviral de gran actividad (TARGA) puede aumentar el riego de infecciones oportunistas, incluida la cistoisosporiasis. Se describe el caso de infección por C. belli en un paciente colombiano con HIV, que presentó un síndrome gastrointestinal crónico e incumplía el tratamiento con la TARGA. Después del diagnóstico parasitológico, el paciente fue tratado con trimetoprim-sulfametoxazol, lográndose la recuperación clínica y la cura parasitológica. Aunque se ha observado una reducción en el número de casos de C. belli desde la implementación de la TARGA, este parásito aún debe considerarse en el diagnóstico diferencial de las enfermedades diarreicas en pacientes con HIV/sida. Los programas de atención deben incluir intervenciones efectivas que potencien el cumplimiento de la TARGA en estos pacientes.

Common occurrence of Cryptosporidium hominis in children attending day-care centers in Medellin, Colombia.

Cryptosporidium spp. are apicomplexan protozoa associated with chronic diarrhea in AIDS and other immunocompromised patients, and one of the commonest causes of childhood diarrhea and malnutrition, particularly in low-income settings. In Colombia, there are few molecular epidemiological studies on Cryptosporidium spp.; thereby, the transmission dynamics of this parasite in the country is poorly known. This study evaluated the diversity of Cryptosporidium at species, subtype family, and subtype level in children attending various day-care centers in Medellin, Colombia. Two hundred and ninety stool samples from children < 5 years of age were collected from April to November of 2015. All samples were processed by PCR and sequence analysis of the ssu RNA gene and the gp60 gene. An infection rate of 2.4% was observed, with only two Cryptosporidium species identified: C. hominis (6/7) and C. meleagridis (1/7). Cryptosporidium hominis isolates belonged to the subtypes IbA10G2, IaA13R6 and IaA13R7; IIIbA26G1R1 C. meleagridis subtype was also detected. There is a C. hominis predominance in the children evaluated, suggesting an important role of the anthroponotic transmission cycle in the day-care centers analyzed. Further investigation is required to determine infection sources and susceptible hosts in order to define appropriate management of cryptosporidiosis.

Prevalencia de parasitosis intestinal, anemia y desnutrición en niños de un resguardo indígena Nasa, Cauca, Colombia, 2015 / Prevalence of intestinal parasites, anemia and malnutrition among the children of a Nasa indigenous reservation, Cauca-Colombia, 2015 / Incidência de parasitose intestinal, anemia e desnutrição em crianças na reserva indígena de Nasa, Cauca-Colômbia, 2015

Resumen Objetivo: determinar la prevalencia de parasitosis intestinal, anemia y desnutrición en niños de un resguardo indígena Nasa de Caldono, en el departamento del Cauca, y su distribución según variables clínicas, sociodemográficas y de infraestructura sanitaria. Metodología: estudio transversal con fuente de información primaria. La muestra de estudio estuvo formada por 62 niños, a quienes se les hicieron evaluación parasitológica en materia fecal, mediciones antropométricas para evaluar el estado nutricional y determinar la prevalencia de diferentes tipos de desnutrición y medición de hemoglobina para establecer la anemia. La descripción del grupo se realizó con medidas de resumen para la edad y frecuencias para las demás variables, se calculó la prevalencia de los tres eventos (parasitosis, desnutrición, anemia) y se exploró su asociación con variables independientes mediante pruebas de hipótesis. Se usó el programa SPSS 22.0. Resultados: se encontró una prevalencia de parasitosis intestinal de 95,2%, anemia de 21,0% y desnutrición crónica de 35,5%. A pesar de no hallar asociación estadística con las condiciones sociodemográficas y sanitarias, se encontró elevada frecuencia de factores de riesgo para los tres eventos, como la baja escolaridad de los padres, baja disponibilidad de acueducto y alcantarillado, y una elevada morbilidad sentida. Conclusión: la comunidad indígena evaluada presentó altas prevalencias de parasitosis intestinal, anemia y desnutrición, lo que representa implicaciones prácticas para la orientación de los programas de salud indígena; la exploración de asociaciones requiere estudios con mayor tamaño de muestra que garanticen una mayor potencia estadística.

Abstract Objective: to determine the prevalence of intestinal parasitosis, anemia and malnutrition among children of a Nasa indigenous reservation from Caldono in the Colombian department of Cauca, and their distribution according to clinical, sociodemographic and healthcareinfrastructure variables. Methodology: a cross-sectional study with a primary source of information. Sixty-two children were evaluated for intestinal parasites via stool analysis. Similarly, anthropometric measurements were used to assess nutritional status and determine the prevalence of various types of malnutrition. Likewise, the presence of anemia was determined by measuring hemoglobin levels. The group was described using summary measures for age and frequency measures for the other variables. Prevalence was calculated for intestinal parasites, anemia and malnutrition, and its association with independent variables was explored using hypothesis testing. The program SPSS 22.0 was used in this study. Results: the prevalence values were: 95.2% for intestinal parasites, 21% for anemia and 35.5% for chronic malnutrition. Although there was no statistical association with sociodemographic and health conditions in the study group, a high frequency of risk factors for intestinal parasites, anemia and malnutrition was found. These factors were: parents with low schooling levels, low availability of aqueducts and sewerage and high perceived morbidity. Conclusion: The evaluated indigenous community had a high prevalence of intestinal parasites, anemia and malnutrition. This has practical implications for the direction that healthcare programs targeting indigenous populations should take. Exploring the associations requires further studies with larger sample sizes which guarantee greater statistical power.

Resumo Introdução: As parasitoses intestinais humanas são consideradas um grave problema de saúde pública em países de baixa renda; além disso, elas apresentam vínculos clínicos e epidemiológicos com anemia e desnutrição, especialmente em comunidades indígenas. Objetivo: Determinar a incidência de parasitose intestinal, anemia e desnutrição em crianças da reserva indígena de Nasa de Caldono, no Departamento de Cauca, e sua distribuição segundo variáveis clínicas, sociodemográficas e de infraestrutura sanitária. Metodologia: Estudo transversal com fonte de informação primária. A mostra de estudo esteve formada por 62 crianças, nas quais foram realizadas avaliações parasitológicas em material fecal, medições antropométricas para que se fosse avaliado o estado nutricional e determinada a incidência de diferentes tipos de desnutrição, e medição de hemoglobina para que se determinasse a anemia. A descrição do grupo realizou-se com medidas de síntese por idade e frequências; para as demais variáveis, calculou-se a incidência dos três eventos (parasitoses, desnutrição, anemia), e explorou-se sua associação com as variáveis independentes mediante verificação da hipótese. Utilizou-se o programa SPSS 22.0. Resultados: Verificou-se uma incidência de parasitose intestinal de 95,2%, anemia de 21,0% , e desnutrição crônica de 35,5%. Apesar de não ter sido comprovada uma associação estatística entre as condições sociodemográficas e sanitárias, verificou-se uma elevada frequência de fatores de risco para os três eventos, como a baixa escolaridade dos pais, baixa disponibilidade de água tratada e saneamento, assim como uma elevada morbidade manifestada. Conclusão: A comunidade indígena avaliada apresentou altas incidências de parasitose intestinal, anemia e desnutrição, o que representa implicações práticas para a orientação dos programas de saúde indígena; a exploração de associações requer estudos com maior grandeza de amostra que garantam um maior poder estatístico.

Microsporidia detection and genotyping study of human pathogenic E. bieneusi in animals from Spain.

Microsporidia are ubiquitous parasites infecting all animal phyla and we present evidence that supports their zoonotic potential. Fecal samples taken from domestic (cats and dogs), farm (pigs, rabbits and ostriches) and wild animals (foxes) from different provinces of Spain were evaluated for microsporidia infection by light microscopy and PCR. After Microsporidia species identification, E. bieneusi genotypes were additionally studied by sequence analysis of the ITS region. Eighty-five samples out of 159 exhibited structures that were compatible with microsporidia spores by Webers stain with 37 of them being confirmed by PCR. Microsporidia species identified included E. bieneusi, E. intestinalis and A. algerae. We report the first diagnosis of E. intestinalis and E. bieneusi in ostriches and A. algerae in pigs. We also provide new information on the molecular characterization of E. bieneusi isolates both in rabbits and ostriches. All of the E. bieneusi genotypes identified belonged to the zoonotic group of genotypes (Group I) including genotypes A (dogs), I (pigs), D (rabbits and foxes) and type IV (ostriches). Our results demonstrate that microsporidia are present in domestic, farm and wild animals in Spain, corroborating their potential role as a source of human infection and environmental contamination.

Prevalencia de parásitos intestinales en niños que asisten al Templo Comedor Sagrado Corazón Teresa Benedicta de la Cruz, del barrio Vallejuelos, Medellín, 2007 / Intestinal parasites prevalence in children from "Templo-Comedor Sagrado Corazón Teresa Benedicta de la Cruz",Vallejuelos-Medellín, 2007.

Introducción: los seres humanos estamos expuestos a los parásitos presentes en el medio en quehabitamos, lo que puede plantear un problema de salud pública, especialmente en los países en vías de desarrollo como Colombia. La población más vulnerable es la infantil, especialmente la de comunidades en condiciones socioeconómicas precarias.Objetivo: determinar la prevalencia de parásitos intestinales en los niños que acuden a un templocomedor en un barrio marginal de Medellín.Métodos: en octubre y noviembre de 2007 se hizo un estudio descriptivo transversal, mediante un coprológico directo y por concentración, en 58 de los 150 niños que acuden al templo-comedor; lo anterior se complementó con una encuesta sobre algunas variables sociodemográficas.Resultados: se halló que 54 de los 58 niños (93%) estaban parasitados y que en 48 de ellos (88,9%) losparásitos eran potencialmente patógenos; entre estos predominó Entamoeba histolytica/dispar(46,6%), seguida por Giardia intestinalis (25,9%), Trichuris trichiura (25,9%), Ascaris lumbricoides (24,1%) y Enterobius vermicularis (8,6%). Se halló multiparasitismo en 21 niños (38,8%). En cuanto a la relación entre algunas variables sociodemográficas y la frecuencia de parásitos solo se halló que el hacinamiento en la vivienda se asociaba significativamente con la presencia de Entamoeba histolytica/dispar y de Blastocystis hominis, y la tenencia de mascotas, con la infección por Enterobiusvermicularis.Conclusión: la prevalencia de parasitosis intestinales hallada en este trabajo superó la de otros grupos tanto colombianos como extranjeros. Se discuten las implicaciones de este hallazgo desde el punto de vista de la salud pública.

Introduction: Human beings are exposed to the parasites present in their habitat. This situation poses a public health problem, especially in underdeveloped countries such as Colombia. The pediatric population is the most vulnerable, particularly that of communities in poor socioeconomic conditions.Objective: To determine the prevalence of intestinal parasites in children attending a social aid institution in a poor neighborhood of Medellín, Colombia.Methods: In October and November 2007 a descriptive cross-sectional study was carried out by means of direct and concentration stool examination in 58 out of 150children attending the aforementioned institution. In addition, a survey was made of some socio-demographicvariables.Results: 54 of the 58 children (93%) were infected by intestinal parasites. In 48 of them (88.9%) potentiallypathogen parasites were present, namely: Entamoeba histolytica/dispar (46.6%), Giardia intestinalis (25.9%), Trichuris trichiura (25.9%), Ascaris lumbricoides (24.1%), and Enterobius vermicularis (8.6%). Twenty one children (38.8%) were infected with either 2 or 3 parasites. The only significant associations between socio demographic variables and parasitic infections were as follows:overcrowding was associated with Entamoeba histolytica/dispar and Blastocystis hominis, and thepresence of pets (mostly dogs) in the house was associated with Enterobius vermicularis.Conclusion: Prevalence rate of intestinal parasites was higher in the studied group than in other communities, both Colombian and from other countries. Implicationsof this finding from the public health perspective are discussed.