Genetic diversity of Blastocystis hominis sensu lato isolated from humans in Poland

INTRODUCTION AND OBJECTIVES: Blastocystis hominis s. l. is one of the most commonly detected protozoa in the human large intestine. The aim of the study was to determine the genetic subtypes of Blastocystis hominis s. l. occurring in humans in Poland. MATERIALS AND METHODS: Stool samples from patients diagnosed in the Laboratory of the Department of Parasitology, National Institute of Public Health ­ National Institute of Hygiene (NIZP-PZH) and in the Parasitology Laboratory of the Hospital for Infectious Diseases in Warsaw were examined. Blastocystis subtypes were assayed based on the fragment of small-subunit ribosomal RNA gene sequences (SSU rDNA). RESULTS: The examined isolates were classified into five Blastocystis subtypes (STs), fifteen of which belonged to ST3, three to ST1, two to ST2, two to ST6, and one isolate belonged to ST7. In three cases the subtype of isolate was not identified. DISCUSSION AND CONCLUSIONS: In Poland, the subtypes ST1, ST2, ST3, ST4, ST6 and ST7 have been reported in humans so far. The ST6 and ST7 subtypes are rarely detected in humans in Europe. In Poland, the ST6 subtype was previously described in chickens. On the basis of the studies, it was found that Blastocystis isolated from humans in Warsaw show high genetic diversity. In order to determine the possible pathogenic potential of individual Blastocystis subtypes, special epidemiological studies are required.

[Expressions and significance of IL-17 and IL-23 in intestinal mucosa of mice infected with Blastocystis hominis].

OBJECTIVE: To study the expressions of interleukin-17 (IL-17) and interleukin-23 (IL-23) in the intestinal mucosa of BABL/C mice infected with Blastocystis hominis. METHODS: A total of 30 BABL/C mice were randomly divided into different groups: an experimental group, an immunosuppressant group and a normal group. Each mouse of the experimental group and immunosuppressant group was administered intraperieneally with dexamethasone (2 mg, gd, for 5 days) and one of the control group was given physiological saline (0.2 ml). In the experimental group, each mouse was infected with Blastocystis hominis (107 parasites per 0.5 ml) by the intragastric infusion method; in the immunosuppressant group and normal group, the mice were fed with equal physiological saline. On the fifth day post-infection, the duodenum, jejunum, ileum and colon of the mice of the 3 groups were taken out for the tissue section. The pathological changes of bowel mucosa were determined by HE staining, and the expressions of IL-17 and IL-23 in different parts of bowel mucosa were determined by immunohistochemistry assay. RESULTS: The pathological examinations showed intestinal mucosa had various degrees of inflammatory changes. The expressions of IL-17 and IL-23 in the intestinal mucosa of the mice in the experimental group was significantly higher than those in the immunosuppressant group or normal group (both P < 0.05). The expressions of IL-17 and IL-23 in the intestinal mucosa of the mice in the immunosuppressant group were similar to those in the normal group (P > 0.05). The expression of IL-17 in the duodenum or jejunum or colon of the mice was significantly higher than that in the ileum in the experimental group (P < 0.05). The expression of IL-23 in the duodenum or jejunum of the mice was significantly higher that that in the ileum or colon in the experimental group (P < 0.05). CONCLUSIONS: IL-17 and IL-23 are highly expressed in the intestinal mucosa of the mice infected with Blastocystis hominis. IL-23 may also be involved in the immunomodulatory effects of Blastocystis hominis infection, which plays a mutual regulatory role with IL-17.

Frecuencia de parasitos intestinales y características epidemiológicas de la población infantil de 1 a 12 años que consulta al ambulatorio urbano tipo II de Cerro Gordo, Barquisimeto, estado Lara: enero-junio 2007 / Frequence of intestinal parasitism and epidemiological characteristics of the 1 to 12 year-old child population treated at the Cerro Gordo type II urban outpatient clinic, Barquisimeto, state Lara: january-june 2007

El objetivo de esta investigación fue determinar la frecuencia de parasitosis intestinales en el área de influencia del Ambulatorio Urbano Tipo II de Cerro Gordo, Barquisimeto, Estado Lara, realizando un estudio descriptivo transversal. Se evaluaron 106 niños entre 1 y 12 años de edad, realizando a cada uno examen de heces directo y concentrado con la técnica de Ritchie, demostrándo se parasitosis intestinal en 42,5%, predominando en escolares (48,9%), sin diferencias según el género. El agente más frecuente fue B. hominis (42,2%), seguido de G. lamblia (37,8%), Complejo Entamoeba histolytica/Entamoeba dispar (13,3%), H. nana (11,1%) y A. lumbricoides (4,4%). Se encontró parasitado 41,7% de niños con estado nutricional normal y 35,7% de malnutridos. La presencia de parasitos intestinales mostró relación con la disposición inadecuada de basura (p=0.048). El lavado inadecuado de las manos se relacionó con prurito anal (p=0.008). La calidad inadecuada del agua se relacionó con Blastocistosis (p= 0,025) y comensales (p= 0,035). No hubo relación entre parasitosis intestinales y síntomas gastrointestinales, estrato social, disposición de excretas, presencia de vectores en el hogar, lavado y conservación de alimentos, frecuencia de recolección de basura, lavado de manos, antecedente de tratamiento antiparasitario y familiar parasitado

A cross-sectional study was conducted to determine intestinal parasitism in children treated at the “Cerro Gordo” Type II Urban Outpatient Clinic in Barquisimeto, Lara. Feces samples were collected from 106 children (1-12 years old) and analyzed using both direct and Ritchie´s technique analyses, demonstrating intestinal parasitism in 42.5% of the children, predominantly of school age (48.9%), but independent of gender. The most frequent agent was Blastocystis hominis (42.2%), followed by Giardia lamblia (37.8%), Entamoeba histolytica/Entamoeba dispar Complex (13.3%), Hymenolepis nana (11.1%) and Ascaris lumbricoides (4.4%). For children with a normal nutritional condition, 41.7% had parasites, while this value was 35.7% for nutritionally undernourished children. The presence of intestinal parasites showed relations to the community’s trash collection management program status (p=0.048). Poor hand washing habits were significantly associated with anal pruritus (p=0.008). Inadequate water quality was related to blastocystosis (p= 0.025) and comensals (p= 0.035). The presence of parasites was not associated with specific gastrointestinal symptoms, socioeconomic status, disposition of excreta, presence of vectors in the home, food washing and storage, frequency of garbage collection, washing of hands, family parasitism history and anti-parasite treatment antecedents

Intestinal parasites in immigrants in the city of Naples (southern Italy).

The present study was aimed at carrying out a cross-sectional copromicroscopic survey of helminths and intestinal protozoa in immigrants in Naples (southern Italy). Between October 2008 and November 2009, a total of 514 immigrants were tested comparing the FLOTAC dual technique and the ethyl acetate concentration technique. Combined results of the two techniques served as a diagnostic 'gold' standard and revealed an overall prevalence of parasitic infections of 61.9% (318/514). The ethyl acetate concentration technique detected a low number of positive results (49.0%) and this was confirmed for each helminth/protozoa species detected. Among helminths, Trichuris trichiura (3.9%), hookworms (3.7%) and Ascaris lumbricoides (1.4%) were the most prevalent. Strongyloides stercoralis (0.4%), Enterobius vermicularis (0.4%), Schistosoma mansoni (1.0%), Hymenolepis nana (1.6%) and Taenia spp. (0.2%) were also found, as well as zoonotic helminths, as Trichostrongylus spp. (0.8%) and Dicrocoelium dendriticum (0.8%). As regard to pathogenic protozoa, Blastocystis hominis was the most commonly detected (52.7%), followed by Entamoeba histolytica/Entamoeba dispar/Entamoeba moshkovskii (11.9%) and Giardia duodenalis (4.5%). Several issues concerning diagnosis, epidemiology and public health impact of parasitic infections in immigrants are offered for discussion. In conclusion, the present paper pointed out the need of better diagnosis and cure of the immigrant population in order to improve access to health care of this neglected and marginalised population group, for its own protection and care.

Presencia de Blastocystis hominis en escolares de un asentamiento humano del distrito de San Juan de Lurigancho, ciudad de Lima / Presence of blastocystis hominis in schoolchildren of a shantytown from San Juan de Lurigancho district, Lima city

Objetivo: Evaluar la presencia de B. hominis en escolares del asentamiento humano ôEnrique Montenegroõ del distrito de San Juan de Lurigancho, Lima, Perú. Material y métodos: Se procesaron 84 muestras fecales de niños entre 6 y 11 años. Se utilizó el examen directo y la técnica de sedimentación de Ritchie. Resultados: Fueron diagnosticados 34 casos positivos (40,4%) para B. hominis. No se observó diferencias de infección por parásitos según el sexo de las personas (p > 0,05). Conclusiones: La presencia de B. hominis en el grupo estudiado fue elevada.

Objective: The aim of this study was to evaluate the presence of B. hominis in schoolchildren of the shantytown ôEnrique Montenegroõ, San Juan de Lurigancho district, Lima, Peru. Material and methods: It was processed 84 fecal samples from children between 6 and 11 years old. Direct exam and sedimentation technique of Ritchie was utilized. Results: Were registered 34 (40.4%) positive cases for B. hominis. No differences by sex was observed (p > 0.05). Conclusions: The B. hominis presence was high in the group studied.

Prevalencia de enteroparásitos y factores ambientales asociados en dos comunidades indígenas del estado Zulia / Prevalence of enteric parasites and related environmental factors in two native communities of Zulia state

El objetivo de la investigación fue relacionar la prevalencia de enteroparásitos con los factores ambientales en dos comunidades indígenas del Estado Zulia. Para ello se analizaron muestras fecales, mediante examen coproscópico y concentrado, de 168 individuos Japrería ubicados en la Sierra de Perijá y 283 Añú en la Laguna de Sinamaica. Se evaluaron muestras de suelos de las zonas respectivas, midiéndose pH, carbono orgánico, conductividad eléctrica, fósforo extraíble, calcio, magnesio y potasio intercambiables, y textura. Datos de precipitación también fueron analizados. Se encontró una elevada prevalencia de enteroparásitos en ambas comunidades (Japrería 83,93 por ciento, Añú 85,16 por ciento). Predominaron los protozoarios y el poliparasitismo, observándose Blastocystis hóminis en primer lugar en ambas poblaciones. En relación a los helmintos, Ancylostomídeos prevaleció en los Japrería y Trichuris trichiura en los Añú. El suelo de la localidad Japrería fue menos arenoso que el de la Añú, registrándose en la primera, mayor precipitación promedio anual. Se concluye que dentro de los factores ambientales evaluados, el suelo es importante en función de su textura, cobertura vegetal y precipitación, que influyen directamente en su capacidad para retener la humedad, constituyéndose en un elemento que determina diferentes patrones de distribución en la prevalencia de geohelmintos.

The objective of the investigation was to relate the prevalence of enteric parasites to environmental factors in two native communities of Zulia State. Fecal samples were analyzed using the copro-parasitology test and concentration technique, for 168 Japrería individuals located in the Perij  Mountain Range and 283 Añú in the Sinamaica Lagoon. Soil samples from the respective zones were evaluated, measuring pH, organic carbon, electric conductivity, extractable phosphorus, calcium, magnesium, interchangeable potassium and texture. Precipitation data were also analyzed. A high prevalence of enteric parasites was found in both communities (Japrer¡a 83.93 percent, Añú 85.16 percent). Protozoa and polyparasitism dominated, observing Blastocystis hóminis in first place for both populations. Regarding helminths, Ancylostom¡deos prevailed among the Japrer¡a and Trichuris trichiura among the Añú. Soil at the Japrería locality was less sandy than that of the Añú and received greater annual average precipitation. Conclusions were that among the environmental factors evaluated, the soil is important because of its texture, vegetable cover and precipitation, influencing its capacity to retain humidity, an element that determines different distribution patterns in the prevalence of geohelminths.

Frequência de Blastocystis hominis e outras enteroparasitoses em amostras fecais analisadas no Laboratório de Parasitologia da Faculdade de Medicina de Marília-SP / Frequency of Blastocystis hominis and other intestinal parasites in stool samples examined at the Laboratory of Parasitology of the Faculty of Medicine of Marilia, Sao Paulo, Brazil

Com o objetivo de avaliar a freqüência de Blastocystis hominis, parasito há pouco tempo reconhecido como protozoário, foram submetidas a exame amostras fecais de 6.559 pacientes encaminhados ao Laboratório de Parasitologia da Faculdade de Medicina de Marília. Foram utilizados os métodos de Faust, Kato-Katz, Rugai e direto, encontrando-se 1.097 (16,7por cento) amostras positivas para B. hominis, entre as quais as maiores porcentagens referem-se às faixas etárias acima de 7 anos com uma diferença estatisticamente significativa em relação aos pré-escolares (p<0,0001). Outras parasitoses também foram consideradas: Giardia duodenalis foi o outro parasito mais freqüente (5,6por cento), principalmente em crianças até 6 anos; Strongyloides stercoralis e Trichuris trichiura foram, significativamente, mais freqüentes que as demais helmintíases. Os resultados mostram a situação das parasitoses intestinais em nossa região, destacando-se a elevada porcentagem de exames positivos para B.hominis.

Perfil clínico-parasitológico de pacientes con VIH/SIDA y diarrea crónica atendidos en el Hospital Escuela del 2003 al 2005 / Clinic and parasitological profile of HIV/AIDS patients treated in the Hopital Escuela during 2003-2005

OBJETIVOS. Determinar la prevalencia de microorganismos (MO) identificados en las muestras de heces y caracterizar clínicamente los pacientes con diarrea crónica y VIH/SIDA atendidos en el Hospital Escuela, Tegucigalpa, Honduras. METODOLOGÍA. Se seleccionaron 142 pacientes internados o atendidos en la Consulta Externa. A través de un instrumento se recolectó la información clínica y de laboratorio. Las muestras de heces fueron procesadas rutinariamente en el Departamento de Laboratorios Clínicos. La información se proceso utilizando los programas estadísticos Epi-info versión 6.04d y SPSS versión 13. RESULTADOS. Entre los 142 pacientes estudiados, predominó el sexo masculino(52%) con edad promedio de 35 años (rango de 18-67) y conteo de CD4 <200 cel/mm 91 pacientes (80.5%). En 66 pacientes (46.5%) se logró identificar al menos un microorgamismos (18 diferentes agentes en 96 muestras de heces). Los microorgamismos más frecuentemente encontrados fueron Blastocystis hominis (21.9%), Cryptosporidium spp. (16.7%) y Strongyloides stercoralis (9.4%). Las infecciones por apicomplexa fueron casi seis veces más frecuente (OR= 5.9) en pacientes con diarrea crónica y VIH/SIDA, especialmente en aquellos con conteo de CD4 <200 cel/mm3 (p<0.05). En 5 muestras de heces (5.2%) se aislaron levaduras y en 14 pacientes (21.2%) se identificaron flagelados comensales. No se aislaron bacterias. CONCLUSIONES. La enfermedad diarreica continúa siendo un problema importante entre los pacientes VIH/SIDA atendidos en el Hospital Escuela. La asociación VIH/ apicomplexa intestinales continúa siendo frecuente y actualmente son las únicas infecciones parasitarias oficialmente reconocidas como enfermedad definitoria de SIDA...

Prevalencia de parasitosis intestinales en el Ambulatorio Militar "La Rosaleda" 2004 / Prevalence of the intestinal diseases parasitic in the Ambulatory Military La Rosaleda 2004

Conocer la prevalencia y la distribución por edad y sexo de parasitosis intestinales producidas por Entamoeba histolytica, Blastocystis hominis Endolimax nana, en la población del Ambulatorio Militar "La Rosaleda" 2004. Estudio descriptivo transversal de prevalencia con análisis bivariado de 754 pacientes de diversas edades y sexo, que asistieron durante el año 2004 al Ambulatorio Militar "La Rosaleda". Se les realizó examen simple de heces y coloración rápida con lugol. Se estudiaron 754 pacientes, 402 femeninos y 352 masculino, con edades comprendidas entre 0-94 años. La prevalencia de las parasitosis intestinales fue de 17,37 por ciento, obteniendo la mayor tasa Blastocystis hominis. La prevalencia general de Blastocystis hominis fue 10,34 por ciento, Entamoeba histolytica 4,64 por ciento, siendo los grupos etarios más afectados de 3-10 años y 21-35 años, en ambas parasitosis y ambos sexos. En el caso de Endolimax nana la prevalencia fue 2,39 por ciento, siendo más frecuente en mujeres con edades entre 36-50 años. El área de influencia del Ambulatorio Militar "La Rosaleda" está constituida por comunidades que cuentan con adecuada provisión de servicios básicos (agua potable, disposición de aguas servidas). Llama la atención la alta prevalencia de estas parasitosis en la población, sobre todo en adultos jóvenes. De esta información se puede inferir que la vía de transmisión más probable es a través de alimentos contaminados. La investigación parasitológica de los establecimientos de comida rápida y ambulante de la zona puede servir de base para estudios posteriores.

Elevada prevalencia de blastocystis hominis en manipuladores de alimentos de los mercados públicos de la zona sud de la ciudad de La Paz / A alta prevalência de Blastocystis hominis entre manipuladores de alimentos em mercados públicos na zona sul da cidade de La Paz

Objetivo. Determinar la prevalencia de blastocystis hominis y otros enteroparásitos en manipuladores de alimentos de los mercados públicos de la zona sud de la ciudad de La Paz. Diseño. Descriptivo transversal. Participantes. Manipuladores de alimentos de los mercados: Achumani, Corazón de Jesus, 16 de Julio y la Merced de la ciudad de La Paz. Lugar. Departamento de patología, cátedra de parasitología. Laboratorio de parasitología. Material y Métodos. Se evaluaron318 muestras de heces, correspondientes a 106 vendedores de alimentos, por examen directo, método de concentracíon de Ritchie modificado y sedimentación espontánea en tubo. Resultados. La prevalencia de la protozoosis intestinal fue de 89,6 por ciento. Los protozoos detectados fueron blastocystis hominis, giardia duodenalis, entamoeba coli, chilomastix mesnili, endolimax nana, lodamoeba butschlii y retortamonas intestinalis. B.hominis fue el protozoo mas frecuente (80,2 por ciento). Se destaca la ausencia de helmintos. En las 101 mujeres y 5 varones, se observó que B. hominis fue más común en el rango de edad de 26 a 37 años (31,8 por ciento) ( p)0.05 ). Las secciones de abarrotes, verduras, comida, jugos y otras mostraron prevalencias entre 29,4 por ciento y 12,9 por ciento, sin embargo, no hubo diferencias significativas ( p)0.05 ). De los 85 manipuladores de alimentos infectados con B. hominis, 13 tenían únicamente este parásito y 72 estaban asociados a otras especies. La combinación estuvo representada por dos, tres y cuatro especies diferentes. Las asociaciones más frecuentes y estadísticamente significativas ( p(0.05 ) fueron con los protozoarios, E. coli y Ch. mesnili. Conclusión. Este es el primer trabajo en Bolivia, donde se determina los valores más altos de prevalencia de B. hominis en la población estudiada, lo que indica...

ObjectiveTo determine the prevalence of Blastocystis hominis and other intestinal parasites among food handlers in South markets, La Paz City.DesignCross-sectional descriptive,ParticipantsFood handlers of the Achumani, Corazón de Jesus, 16 de Julio, and la Merced south markets, La Paz City.PlaceDepartment of Pathology, Laboratory of Parasitology.Material and methodsA serial coproparasitological analysis was performed (3 samples) in 106 food handlers (308 samples) were evaluated by direct examination (saline solution and lugol), modified Ritchie, and simple sedimentation in tube.ResultsThe prevalence of intestinal protozoosis was 89,6%. The detected protozoos was Blastocystis hominis, Giardia duodenalis, Entamoeba coli, Chilomastix mesnili, Endolimax nana, Iodomoeba bütschlii. Retortamonas intestinalis. B. hominis was the most frequently detected protozoa (80,2%). There is absence of helminths.In the 101 women and 5 men, B. hominis was more common in the age range from 26 to 37 years (31,8%) (p>0.05).The sections of groceries, vegetables, food, juices and others, showed prevalences between 29,4% and 12,9%, however, no significant differences were found (p>0.05).Of the 85 food handlers infected with B. hominis, 13 had this parasite only, and in 72 cases B. hominis was associated to other species. The combination was of two, three, and four different species. The most frequent and statistically significant associations (p <0.05) were with the protozoa: E. coli and C. mesnili.ConclusionThis is the first time in Bolivia that a highest prevalence of B. hominis is found in a population group, what indicates a high index of fecal contamination.Therefore, this should be a high-priority group to take into account when measures of promoting prevention and control of these parasites are taken in the population, because the food handlers are an epidemically important group for the dissemination of intestinal parasites.

Blastocystis hominis infection in irritable bowel syndrome patients.

Irritable bowel syndrome (IBS) is a functional bowel disorder in which abdominal pain is associated with a defect or a change in bowel habits. Subtle inflammation, especially after infectious enteritis, has been sometimes suspected as one mechanism of pathogenesis. This research was performed (1) to evaluate the prevalence of parasitic infections and (2) the possible association of IBS and parasitic infections. Fifty-nine IBS patients were recruited using symptom-based criteria (Rome Criteria II) with an absence of intestinal parasitic infection by direct smear method. Stool samples of individual patients were examined using 7 methods, ie examination for stool occult blood, simple saline smear method, formalin-ether technique, culture for Blastocystis hominis, modified trichrome stain, modified Ziehl-Neelsen method, and trichrome stain for parasitic and bacterial infections. Of the 59 patients, stool samples of 13 patients (22.1%) were positive for parasites. These were B. hominis (13.6%), Strongyloides stercoralis larvae (1.7%), Giardia lamblia cysts (1.7%), and non-pathogenic protozoa, ie Endolimax nana cysts (5.1%). The prevalence rate of parasitic infections in the control group (20%) was not statistically different from the patients. There was no statistical difference between B. hominis infection in IBS patients and control was found in this study (p = 0.87). In the IBS group, B. hominis infection predominated (13.6%), while other parasitic infections were found in 8.5%. The culture method for B. hominis is more sensitive than the direct (simple) stool smear method, which is the routine diagnostic method in most laboratories. These results were also found in control group.

[Seasonal variation of intestinal protozoa infections in outpatients of the north section of Santiago, Chile. 1995-1996]. / Variación estacional de las infecciones por protozoos intestinales en pacientes ambulatorios del sector norte de Santiago, Chile, 1995-1996.

Formalin preserved fecal samples from 6,058 and 5,863 outpatients were examined for intestinal parasites during 1995 and 1996 respectively. Prevalence rates of infections by intestinal protozoa in both years were similar. By age group (0-9, 10-19 and > 20 years old) Blastocystis hominis was observed in 18.6-19.3, 37.0-31.1 and 25.3-25.4% in 1995-1996 respectively. Prevalence of Giardia intestinalis infections decreased from 16.6-17.4% in the 0-9 year-old children group to 4.1-4.5% in patients over 20 years. Overall percentages of infection by Entamoeba histolytica varied between 4.2 and 10.9. Rates of infections by G. intestinalis, E. histolytica, and Entamoeba coli observed during rainy-cold months (april-september) of the year versus drywarmy period (october-march) were the same. On the contrary, more cases of B. hominis infection 25.8% versus 18.2% (this difference being statistically significant, p > 0.001) were observed during rainy-cold months of the year.

Blastocystis hominis en niños con gastroenteritis estudiados en dos centros hospitalarios pediátricos de Caracas: Venezuela junio 1993-julio 1994 / Blastocystis hominis in children with gastroenteritis: study in two pediatrics hospital centers of Caracas: Venezuela june 1993-july 1994

El problema de la diarrea aguda infantil (DAI), es de caracter mundial. En Venezuela no había una visión clara sobre la importancia de los agentes parasitarios en la etiología de la DAI Estudiamos 412 niños de 0 a 3 años de edad con diarrea aguda y 39 controles, entre junio de 1993 y julio de 1994. los métodos parasitológicos empleados fueron: Exámen microscópico directo con solución salina 0.85 por ciento, Lugol, coloración de Quensel, Sudán III, coloración con hematoxiclina férrica, Ziehl Neelsen, cultivo en medio de Boeck modificado y se realizó estudio bacteriológico y viral, en el marco del proyecto CONICIT MPS-RP-IV: 140031. Se encontraron parásitos intestinales en 33 niños (8,3 por ciento), de los cuales, 17 (51,5 por ciento) presentaron Blastocystis hominis,14 (42,42 por ciento)Giardia lamblia, 3 (8,8 por ciento), Ascaris lumbricoides, Entamoeba histolyca, 1 (3,0 por ciento), Trichuris trichuria, 1 (3,0 por ciento). De los 17 casos positivos para Blastocystis hominis, 2 de ellos resultaron asociados a bacterias enteropatógenas (Shigella flexneri y Enterobacter cloacae) y 1 a Rotavirus. Los hallazgos demuestran que el Blastocystis hominis es el parásito más frecuente y permite sugerir que en los casos donde no hay asociación con otros microorganismos, es el agente causal del cuadro gastrointestinal