Prevalencia de parasitosis intestinal en escolares de zonas semirrurales de Ecuador II / Prevalence of intestinal parasitosis in schoolchildren from semi-rural areas of Ecuador II

La mayor proporción de individuos afectados por la parasitosis intestinal corresponde a la población infantil, debido a su inmadurez inmunológica y poco desarrollo de hábitos higiénicos y la práctica de jugar con tierra. Los estudios realizados en zonas rurales a nivel internacional sobre prevalencia de parasitosis intestinales en niños, reportan cifras que varían entre el 30 y 90 %. En los países afectados, entre los que figura notablemente Ecuador, las infecciones parasitarias intestinales están estrechamente relacionadas a los procesos de desarrollo económico y social. Ochenta y un escolares de zonas semirrurales (20%) cumplieron con los criterios diagnósticos de parasitosis intestinal. La Blastocystis sp. (10%), fue la especie parasitaria más comúnmente encontrada, en segundo lugar E. nana (3,7%) y en tercer lugar Complejo Entamoeba (2,5%). Específicamente en la población infantil de zonas semirrurales no se han realizado estudios de pesquisaje recientes en el contexto ecuatoriano y se ignora qué consecuencias pudo tener la pandemia de COVID-19 para la prevalencia de estas infecciones. Se desarrolló una investigación sobre los antecedentes y prevalencia de parasitosis intestinal en escolares de zonas semirrurales de Ecuador a fin de aportar información empírica al respecto(AU)

The largest proportion of individuals affected by intestinal parasitosis corresponds to the child population, due to their immunological immaturity and little development of hygienic habits and the practice of playing with dirt. - Studies carried out in rural areas at the international level on the prevalence of intestinal parasites in children, report figures that vary between 30% and 90%. In the affected countries, including notably Ecuador, intestinal parasitic infections are closely related to the processes of economic and social development. Eighty-one schoolchildren from semi-rural areas (20%) met the diagnostic criteria for intestinal parasitosis. The Blastocystis sp. (10%), was the most commonly found parasitic species, in second place E. nana (3.7%) and in third place Entamoeba Complex (2.5%). Specifically, in the child population of semi-rural areas, no recent screening studies have been carried out in the Ecuadorian context and the consequences the COVID-19 pandemic could have had on the prevalence of these infections are unknown. An investigation was developed on the background and prevalence of intestinal parasitosis in schoolchildren from semi-rural areas of Ecuador in order to provide empirical information in this regard(AU)

Blastocystis spp. y su asociación con otros parásitos intestinales en niños de edad preescolar, estado Sucre, Venezuela / Blastocystis spp. and their association to other intestinal parasites in preschool children from Sucre State, Venezuela

Introducción: Blastocystis spp. es uno de los parásitos intestinales más comunes en el ser humano y su patogenicidad sigue siendo controvertida. Objetivo: Determinar la prevalencia de Blastocystis spp. y su asociación con otros parásitos intestinales a niños en edad preescolar. Métodos: Se procesaron 90 muestras fecales provenientes de niños en edad preescolar. Las técnicas copro-parasitológicas usadas fueron: examen directo con solución salina (0,85 por ciento) y lugol. Se usó la prueba chi cuadrado para demostrar la independencia entre las variables: parasitosis, sexo y edad. Se determinó el índice de afinidad de Fager para establecer las asociaciones entre los principales enteroparásitos identificados. Resultados: Se encontraron 68 niños parasitados, con 75,6 por ciento de prevalencia. No hubo diferencias significativas con respecto a la edad y el sexo (p> 0,05). Los parásitos más comunes fueron: Blastocystis spp. (45,6 por ciento), Endolimax nana (30,9 por ciento), Entamoeba coli (26,5 por ciento), y como único helminto, Enterobius vermicularis (1,5 por ciento). El 42,6 por ciento estuvo monoparasitado y 57,4 por ciento biparasitados. Los índices de afinidad (IAB) y pruebas de "t" efectuadas, señalaron asociación significativa entre Blastocystis spp. y los protozoarios E. nana y E. coli. Conclusiones: Se determina una elevada prevalencia de Blastocystis spp. y especies comensales intestinales, todas indicadoras de contaminación fecal, en que probablemente factores ambientales y socioculturales promueven su transmisión. Este tema debe continuarse y profundizarse por la connotación que ha adquirido este parásito en los debates científicos actuales, tanto en el ámbito nacional como internacional(AU)

Introduction: Blastocystis spp. are among the most common intestinal parasites affecting humans. Their pathogenicity continues to be a topic of debate. Objective: Determine the prevalence of Blastocystis spp. and their association to other intestinal parasites in preschool children. Methods: Analysis was performed of 90 stool samples from preschool children. The coproparasitological techniques used were direct examination with 0.85 percent saline solution and lugol. The chi-square test was used to show the independence between the variables parasitic infection, sex and age. Fager's affinity index was determined to establish associations between the main enteroparasites identified. Results: The study found 68 children infected with parasites, for a 75.6 percent prevalence. There were no significant differences with respect to age and sex (p> 0.05). The most common parasites were Blastocystis spp. (45.6 percent), Endolimax nana (30.9 percent) and Entamoeba coli (26.5 percent). The only helminth found was Enterobius vermicularis (1.5 percent). 42.6 percent of the children were infected with one parasite and 57.4 percent with two. The affinity index (IAB) and t tests performed revealed a significant association between Blastocystis spp. and the protozoa E. nana and E. coli. Conclusions: High prevalence was determined of Blastocystis spp. and intestinal protozoan species, all of which were indicative of fecal contamination. Environmental and sociocultural factors are likely to facilitate their transmission. This topic should continue to be addressed and examined due to the relevance of this parasite in current scientific debate, both nationally and internationally(AU)

Current status of research regarding Blastocystis sp, an enigmatic protist, in Brazil

The present study aimed to evaluate the occurrence of Blastocystis sp. in Brazilian studies over a period of years (2000-2020), as well as point out relevant aspects of this enigmatic organism. We performed a literature search using six sources of international databases. The data were divided into diagnostic by parasitological and molecular techniques, and relevant aspects. After applying the inclusion and exclusion criteria, 52 studies were included in the final analysis. The occurrence of Blastocystis sp. in Brazil ranged from 0.5% to 86.6%, as determined using parasitological techniques. The highest occurrence was in the North (27.3%) and the lowest, in the Midwest region (13.4%). In Brazil, most studies have employed molecular techniques and are concentrated in the Southeast region. The Blastocystis sp. subtype ST3 had the highest average positivity, followed by ST1 and ST2. These findings represent a panorama that reflects the reality of Brazil; thus, we believe that the effectiveness of parasitological diagnosis should be considered with regard to making an appropriate choice of technique for detecting Blastocystis sp. Additionally, we emphasize the importance of further studies in the context of molecular epidemiology with regard to this genus. Blastocystis sp. is not well understood yet, and very little information regarding this genus is available; hence, further research regarding this genus is urgently needed.

Molecular characterization of Blastocystis subtypes isolated in the city of Uberaba, Minas Gerais State, Brazil

Abstract INTRODUCTION Blastocystis is an intestinal protozoan that may play a role in the pathogenicity of humans. This study aimed to (i) genetically characterize Blastocystis isolates obtained from human fecal samples and the water supply of the city of Uberaba, Minas Gerais, Brazil, and (ii) to verify the phylogenetic relationship between these isolates. METHODS Blastocystis species present in 26 fecal samples obtained from humans and animals from Uberaba were genetically characterized by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction-sequence-tagged sites. All amplicons were partially sequenced and/or defined according to the GenBank classification. RESULTS Polymerase chain reaction amplicons were generated from 21 human isolates and 18 water samples. The subtypes defined were ST1 (53.3%), ST3 (40.0%), and ST2 (6.7%) for human isolates; ST10 (100%) for bovine isolates; and ST5 (50.0%), ST1 (25%), and ST3 (25%) for pigs. Sequencing of polymerase chain reaction products showed a 98%-99% identity for the Blastocystis sequences deposited in GenBank, except for sequences from water samples that showed the identity of algae sequences. Phylogenetic analysis of Blastocystis sequences showed two distinct groups, one of which was principally formed by ST1, ST5, and ST10, and the other by isolates characterized as ST3 and ST7. Both clades showed human and animal sequences, reinforcing the notion that Blastocystis subtypes are not host-specific. CONCLUSIONS The data showed that Blastocystis subtypes circulating in Uberaba are ST1-ST3, ST5, and ST10, present in both humans and animals, demonstrating that the Blastocystis subtypes are not host-specific; that is, zoonotic transmission is possible.

Asociación entre blastocistosis y anemia por déficit de hierro en mujeres embarazadas en el municipio La Lisa, La Habana, Cuba / Association between Blastocystosis and Iron Deficiency Anemia in Pregnant Women in La Lisa Municipality, Havana, Cuba

Introducción: Estudios recientes encontraron asociación entre blastocistosis y anemia por déficit de hierro. Uno de ellos demostró que en mujeres embarazadas la infección por Blastocystis spp. es un factor de riesgo para padecerla y puede tener consecuencias adversas tanto para la madre, como para el feto que en casos extremos puede conducir a mortalidad maternofetal. Objetivo: Conocer la prevalencia de blastocistosis en mujeres embarazadas y su posible asociación con la anemia ferropénica. Métodos: Se realizó un estudio parasitológico, clínico y epidemiológico, de tipo descriptivo y de corte transversal, al universo de las gestantes atendidas en tres policlínicos del municipio La Lisa, entre julio 2017 y junio 2018. Resultados: De 135 embarazadas, 43 (31,9 por ciento) estaban infectadas por protozoos parásitos. De estos, Blastocystis spp, fue el más prevalente (28,9 por ciento). Del total de gestantes, 41 padecían de anemia. En la mayoría de estas (85,4 por ciento), la anemia clasificaba como ferropénica. La proporción de embarazadas parasitadas por Blastocystis spp. que padecían este tipo de anemia, en relación con las gestantes que no estaban infectadas por ese protozoo y también padecían de ese tipo de anemia fue significativamente mayor (p lt; 0,05). Conclusiones: Blastocistosis es una parasitosis de prevalencia creciente e insuficientemente conocida. Iniciativas para mejorar conocimientos, percepciones y prácticas en relación con su diagnóstico, tratamiento y control son perentorias a nivel popular y académico. Las estrategias de comunicación que se implementen deben informar sobre las posibles consecuencias clínicas de la infección en relación con la mujer embarazada(AU)

Introduction: Recent studies found an association between blastocystosis and iron deficiency anemia. One of them showed that the infection with Blastocystis spp is a risk factor for in pregnant women to suffer. This infection can have adverse consequences for both the mother and the fetus. In extreme cases it can lead to maternal and fetal mortality. Objective: To know the prevalence of blastocystosis in pregnant women and its possible association with iron deficiency anemia. Methods: A parasitological, clinical and epidemiological study, descriptive and cross-sectional was conducted on the universe of pregnant women treated in three clinics in La Lisa municipality from July 2017 to June 2018. Results: We found 43 (31.9 percent) pregnant women infected by parasitic protozoa out of 135 who were studied. Blastocystis spp, was the most prevalent (28.9 percent). 41 pregnant women suffered from anemia. In most of them (85.4 percent), anemia classified as iron deficiency. The proportion of pregnant women parasitized by Blastocystis spp who suffered from this type of anemia was significantly higher (p lt;0.05) in relation to pregnant women who were not infected by that protozoan and also suffered from that type of anemia. Conclusions: Blastocystosis is a parasitosis of increasing prevalence which is insufficiently known. Initiatives to improve knowledge, perceptions and practices are peremptory to their diagnosis, treatment and control at the general and academic levels. The communication strategies that are implemented should inform about possible clinical consequences of this infection in pregnant woman(AU)

Molecular Detection and Subtyping of Blastocystis in Korean Pigs

Blastocystis is one of the most commonly detected genera of protozoan parasites in the human intestines as well as the intestines of many other species such as pigs in several geographical regions worldwide. However, no studies have examined Blastocystis in pigs in Korea. In this study, PCR and nucleotide sequencing were performed to evaluate the genetic diversity and zoonotic potential of Blastocystis using pig fecal samples. We obtained 646 stool samples from groups of piglets, weaners, growers, finishers, and sows in Korea. A total of 390 Blastocystis-positive samples were identified, and the infection rate was 60.4%. The infection rates were significantly related to age and region. The 4 subtypes (STs) of Blastocystis confirmed by phylogenetic analysis were ST1, ST2, ST3, and ST5, indicating the high genetic diversity of Blastocystis in Korean pigs. ST5 was highly distributed in Korean pigs among detected STs in this study. Some sequences were closely related to those of Blastocystis isolated from humans. This is the first study of Blastocystis in pigs in Korea. Based on the results, Blastocystis is prevalent in Korean pigs. Although a small number of samples were obtained in some areas, the clinical development of Blastocystis infection in pigs and potential for human transmission should be further examined.

Atorvastatin: In-Vivo Synergy with Metronidazole as Anti-Blastocystis Therapy

Blastocystis is an enteric Straminopile in tropical, subtropical and developing countries. Metronidazole has been a chemotheraputic for blastocystosis. Failures in its regimens were reported and necessitate new studies searching for alternative therapeutic agents. Aim of current study is to investigate potential effects of Atorvastatin (AVA) compared to the conventional chemotherapeutic MTZ in experimentally Blastocystis-infected mice. Anti-Blastocystis efficacy of AVA was evaluated parasitologically, histopathologically and by transmission electron microscopy using MTZ (10 mg/kg) as a control. Therapeutic efficacy of AVA was apparently dose-dependent. Regimens of AVA (20 and 40 mg/kg) proved effective against Blastocystis infections with high reduction in Blastocystis shedding (93.4–97.9%) compared to MTZ (79.3%). The highest reductions (98.1% and 99.4%) were recorded in groups of combination treatments AVA 20–40 mg/kg and MTZ 10 mg/kg. Blastocystis was nearly eradicated by the 20th day post infection. Genotype analysis revealed that genotype I was most susceptible, genotype III was less. Histopathologic and ultrastructural studies revealed apoptotic changes in Blastocystis and significant improvement of intestinal histopathological changes more remarkable in combinational therapy groups. Thus, the present study offers AVA as a potential candidate for Blastocystis therapy combined with MTZ.

Coexistencia de colitis linfocítica y enteritis microscópica en pacientes con diarrea crónica / Concurrent lymphocytic colitis and microscopic enteritis in patients with chronic diarrhea

Introducción: Colitis linfocítica y enteritis microscópica son causas relativamente comunes de diarrea crónica y ambas se caracterizan por un infiltrado linfocitico intraepitelial. No existen reportes previos de la coexistencia de ambas entidades. Objetivo: Describir las características clínicas e histológicas de los pacientes que presentan este diagnóstico simultáneamente. Material y métodos: Se seleccionaron pacientes adultos con diarrea crónica que tuvieran biopsia simultánea de colon y duodeno tomados el mismo día, durante los años 2010-2016, en el Servicio de Gastroenterología del Hospital Nacional Daniel Alcides Carrión. Se recopiló información clínica del archivo de historias. Las láminas fueron reevaluadas histológicamente por 3 patólogos. Se realizó estudio inmunohistoquímico de linfocitos intraepiteliales para CD8 y CD3 en 6 casos. Resultados: De 63 pacientes con diarrea crónica y biopsia simultánea de duodeno y colon, se identificó un total de 35 pacientes (55,5%) con diagnóstico simultáneo de enteritis microscópica y colitis linfocítica, 80% fueron mujeres. Se identificó anemia en 28,5% de los pacientes e infestación por Blastocystis hominis en el 31,8.%. En enteritis microscópica, el promedio de linfocitos intraepiteliales con CD8 y CD3 fue 40%, mientras que, en colitis linfocítica, el promedio fue de 37,2% para CD3 y 29,2% para CD8. En 11 de los 35 casos, se pudo obtener biopsias de íleon que fueron diagnosticadas como ileitis linfocítica. En 9 casos se diagnosticó colitis eosinofílica asociada a colitis linfocítica. Conclusión: Se encontró coexistencia de colitis linfocítica, enteritis microscópica y en algunos de ileitis linfocítica en un 55,5% pacientes con diarrea crónica con biopsia duodenal y colónica. Estos resultados abren la interrogante sobre si colitis linfocítica y enteritis microscópica son entidades diferentes o constituyen una sola patología que en algunos pacientes afecta varios segmentos del tubo digestivo.

Introduction: Lymphocytic colitis and microscopic enteritis are relatively common causes of chronic diarrhea and it is characterized by an intraepithelial lymphocytic infiltrate. There have been no previous reports of coexistence between these 2 pathologies. Objective: To describe histological and clinical characteristic in patients with coexistence of lymphocytic colitis and microscopic enteritis. Material and methods: All cases with simultaneous diagnosis of lymphocytic duodenosis and lymphocytic colitis were reevaluated during lapse time 2010-2016 in hospital Daniel Carrion. The slides were reviewed by 3 pathologists and clinical information was obtained from clinical records. Expression of CD3 and CD8 was detected in 6 cases by immunohistochemical assays. Results: A total of 35 patients with coexistence of lymphocytic duodenitis and lymphocytic colitis were selected of the pathology archives, 80% were females, Anemia was identified in 28.5% of patients. Blastocysitis hominis infestation was identified in 31.8%. The mean intraepithelial lymphocyte CD8 and CD3 positive was 40% in microscopic enteritis, while the mean intraepithelial lymphocyte CD3 positive was 37.2% and CD8 positive was 29.2% Additionally, lymphocytic ileitis was diagnosed in 11 of our cases. Eosinophilic colitis was diagnosed in 9 cases of lymphocytic colitis Conclusion: We found that lymphocytic colitis, microscopic enteritis and even lymphocytic ileitis can coexist in a group of patients with chronic diarrhea. These findings bring the question if this concurrence of both pathologies constituted a more generalized gastrointestinal disorder, involving both the large and the small intestines.

Blastocystis spp.: avances, controversias y desafíos futuros / Blastocystis spp.: Advances, controversies and future challenges

Blastocystis spp. es el protista intracelular que se detecta con mayor frecuencia en muestras de materia fecal humana; las tasas de infección pueden superar el 20% en países en vías de desarrollo. El hallazgo de este parásito en heces de diversas especies animales sugiere su potencial zoonótico. La relevancia clínica y el papel patógeno de Blastocystis spp. en el tracto intestinal son inciertos. Varias son las publicaciones que lo reconocen como agente etiológico de desórdenes intestinales como diarrea, enfermedad inflamatoria intestinal y colitis ulcerosa, aunque la patogenicidad de este parásito no ha sido probada. Este amplio rango de respuestas a la infección podría estar relacionado con la diversidad genética de los aislamientos provenientes de hospedadores infectados.

Blastocystis spp. is the most common protozoan detected in human stool samples. In developing countries, infection rates are higher than 20%. The presence of this parasite in the feces of several host species suggests its zoonotic potential. The clinical relevance and the pathogenic role of Blastocystis spp. in the intestinal tract remain unclear. There are several clinical reports that recognize it as the etiologic agent of several intestinal disorders such as diarrhea, inflammatory bowel disease and ulcerative colitis, although the pathogenicity of this parasite has not been proved yet. This wide range of clinical manifestations could be related to the genetic diversity exhibited by this parasite.

Parasitosis y síndrome de intestino irritable / Parasitosis and irritable bowel syndrome

El síndrome de intestino irritable (SII) es un trastorno funcional digestivo de etiología multifactorial. En su fisiopatología se describen diversos factores, tanto biológicos, como psicológicos y ambientales, que afectan el estado de activación de células inmunes en la mucosa intestinal. Entre los factores ambientales se incluye la presencia de alguna parasitosis intestinal. El síndrome de intestino irritable post-infeccioso (SII-PI) es reconocido como un subgrupo de estos trastornos, cuya aparición de los síntomas es posterior a una infección intestinal provocada por agentes microbianos. A pesar de que en Chile hay pocos estudios respecto a la relación entre SII y parasitosis intestinal, se ha descrito la existencia de una asociación positiva entre SII e infecciones por Blastocistis hominis, uno de los parásitos prevalentes en Chile. En otros países, se ha descrito además una relación entre SII, amebiasis y giardiasis. Por la alta prevalencia de parasitosis en nuestro país, existe la necesidad de ampliar los estudios para clarificar la fuerza de la asociación entre parasitosis y SII.

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract characterised by multi-factorial aetiology. In IBS physiopathology are involved diverse factors between them biological, psychosocial, and environmental components which affect the immune activation status of gut mucosa. Among these factors is recognized the intestinal parasitosis. Post-infection IBS (PI-IBS) is recognised as a subgroup of functional disorders whose symptoms onset appear after a symptomatic intestinal infection caused by microbial agents. There are few studies regarding of relationship between IBS and intestinal parasitosis in Chile. However, is has been well described a positive association between IBS and Blastocystis hominis infections, one of prevalent parasites in Chile. In other countries, is also described a relationship between IBS and amebiasis and giardiasis. Both, characterized by a common mode of transmission through water as well as contaminated food. Because the high prevalence of parasitosis in our country it is necessary to expand the association studies to clarify the strength of the parasites ethiology in IBS.

In vivo and in vitro efficacy of Nigella sativa aqueous extract on blastocystis hominis

Metronidazole [MTZ] was the most widely accepted treatment for Blastocystis hominis [B. hominis] with high treatment failure rate, resistance and potential mutagenic and carcinogenic effects so there is urgent need to find out new, effective and safe treatment against B. hominis. The present research aimed to evaluate the therapeutic effect of the aqueous extract of Nigella sativa [NS] at different doses on B. hominis in vitro and in vivo in comparison to MTZ as a control drug. Isolates of B. hominis were obtained from patients complaining of diarrhea and abdominal pain. Isolates were cultured in egg diphasic medium [LE] for in vitro study and to adjust proper inoculating dose for in vivo study. The aqueous extract of NS at concentrations of 100 and 500?g/ml showed a potent lethal effect on B. hominis isolates in vitro. Caecal tissue of experimentally infected and treated mice with two different doses of NS [250 and 500mg/kg/d] were examined histopathologically and compared with that of mice infected and treated by two doses of MTZ [62 and 125 mg/kg/d] as control drug and Infected untreated mice as negative control group. Histopathological examination of infected untreated group showed all pathological degrees in the caecal tissue while infected treated one showed remission of pathological changes especially with higher dose [500mg/kg]. Present study proved that N. sativa had inhibitory effect on B. hominis in vitro and prevented cytopathic effect in infected mice inoculated orally with B. hominis

PATHOGENICITY OF Blastocystis sp. TO THE GASTROINTESTINAL TRACT OF MICE: RELATIONSHIP BETWEEN INOCULUM SIZE AND PERIOD OF INFECTION / Histopatogenicidade de Blastocystis sp. para o trato gastrointestinal de camundongos: relação com inóculo e tempo de infecção

The pathogenic potential of Blastocystis sp. in experimental models requires further investigation. In this work, the pathogenicity of this parasite in the gastrointestinal tract of male Swiss mice was evaluated according to the inoculum size and period of infection. Animals were infected intragastrically, with 100, 500, 1,000, 5,000 and 10,000 Blastocystis sp. vacuolar forms obtained from a mixture of eight human isolates cultured axenically in Jones' medium. After seven, 14, 21, 28 and 60 days of infection, the animals were sacrificed and fragments of the small intestine (duodenum), large intestine, and cecum were subjected to histopathological analysis. Blastocystis sp. triggered an inflammatory response in the different tissues analyzed, with a predominance of mononuclear cells. The parasite was found in the muscular layer of the cecum, showing its invasive character. Larger inocula triggered inflammatory processes earlier (seven days) than smaller ones (from 21 days). We conclude that, in the proposed model, the pathogenicity of Blastocystis sp. isolates that were studied is related to inoculum size and period of infection.

Pouco é sabido sobre o potencial patogênico de Blastocystis sp. em modelos experimentais. Neste trabalho a patogenicidade desse parasito para o trato gastrointestinal de camundongos Swiss machos foi avaliada de acordo com o inóculo e tempo de infecção. Os animais foram infectados, via intragástrica, com 100, 500, 1.000, 5.000 e 10.000 formas vacuolares de Blastocystis sp. obtidos a partir de uma mistura de oito isolados humanos cultivados axenicamente em meio Jones. Após 7, 14, 21, 28 e 60 dias de infecção os animais foram sacrificados e fragmentos do intestino delgado (duodeno), grosso e ceco foram retirados para análise histopatológica. Blastocystis sp. desencadeou resposta inflamatória nos diferentes tecidos analisados, com predominância de infiltrado mononuclear. No ceco o parasito foi encontrado na túnica muscular mostrando seu caráter invasivo. Inóculos maiores desencadearam processos inflamatórios mais precocemente (7 dias) e inóculos menores mais tardiamente (a partir de 21 dias). Conclui-se que no modelo proposto a patogenicidade dos isolados de Blastocystis sp. estudados tem relação com o inóculo e tempo de infecção.

Prevalencia de parasitosis intestinales en unidades educativas de Ciudad Bolívar, Venezuela / Prevalence of intestinal parasites in educational units from Ciudad Bolívar, Venezuela

Introducción: Las parasitosis intestinales a nivel mundial son un problema de salud pública que afecta a los países en las zonas tropicales. Un grupo muy vulnerable a padecer este tipo de infección son los niños. El objetivo de la presente investigación fue determinar la prevalencia general de parásitos intestinales en las Unidades Educativas de Ciudad Bolívar, entre los años 2009 - 2013. Materiales y Métodos: Fueron obtenidos los trabajos de grado sobre el tema del Departamento de Parasitología y Microbiología y así se recolectaron datos sobre edad, sexo, tipo de parasito, especies y asociaciones parasitarias y poder calcular así dicha prevalencia general. Resultados: Se encontró una prevalencia general de 63,1% sin predilección por la edad o sexo. Los tipos de parásitos más prevalentes fueron los protozoarios con 83,5%. Las especies más prevalentes fueron Blastocystis spp con 39,7%, Entamoeba coli con 15,3%, y Giardia intestinalis con 13,4%. Las asociaciones parasitarias más frecuentes Blastocystis sppconEndolimax nana (21,1%) yBlastocystis sppcon Entamoeba coli. (7,4%). Discusión: Los resultados de este estudio guardan relación con estudios realizados a nivel nacional como internacional, con respecto a las prevalencias de parasitosis, el predominio de protozoarios sobre helmintos en los últimos años, y la indistinción de la infección parasitaria con respecto al género. Conclusiones: La prevalencia aquí estudiada a manera general es alta, se recomienda seguir haciendo este tipo de estudios en escuelas para denotar el impacto de estas infecciones en niños y la consecuencia que esto conlleva.

Introduction: The intestinal parasites are a worldwide public health problem that affects countries in tropical and subtropical areas, a very vulnerable group to suffer this kind of infection are children .The objective of this investigation was determine the general prevalence of parasitism intestinal in the Educational Units from Ciudad Bolívar, between the years 2009 - 2013. Materials and Methods: For this were reviewed the degree work’s about intestinal parasitism’s in the Department of Parasitology and Microbiology , ando so data was collected about, age, sex, parasite type, species and parasitic association, and so calculate the general prevalence Results: It was found a general prevalence of 63,1% no predilection for the age or sex. The parasite types more prevalent have be the protozoan with 83, 5%. The species more prevalente heve be Blastocystis spp with 39, 7% Entamoeba coli with 15, 3%, and Giardia intestinalis 13, 4%. The parasitic association most frequent Blastocystis spp / Endolimax nana (21,1%) and Blastocystis spp / Entamoeba coli (7,4%). Discussion: The results of this study relate to the work done at national and international level regarding the prevalence of parasitosis, the predominance of protozoa with respect to helminths, and indistinction of parasitic infection with regard to gender. Conclusions: The prevalence in all years studied here assessed globally is high, it is recommended to keep doing this type of study in schools to denote the impact of these infections in children and the consequences that this entails.

Morbilidad por blastocystis spp. en el hospital pediátrico universitario "William Soler" / Morbidity from blastocystis spp. at "William Soler" university pediatric hospital

INTRODUCCIÓN: blastocystis spp. se considera actualmente un posible nuevo patógeno intestinal, y se reconoce su existencia en edad pediátrica. OBJETIVO: identificar el patrón clínico y epidemiológico de infección por Blastocystis spp. MÉTODOS: estudio descriptivo en 98 pacientes cuyas heces fueron recepcionadas en el Departamento de Parasitología del Hospital Pediátrico "William Soler" (2008 a 2009), en La Habana. RESULTADOS: Blastocystis spp. se manifestó de forma única en 59,2 %, significativamente superior (p= 0,000) respecto a su presentación en coinfección (26,7 %), principalmente con Giardia lambia (17,3 %) y Entamoeba histolytica/E. dispar (11,2 %). En infección solo por Blastocystis spp. (n= 58), la tasa de infección se incrementó de 47,2 % (1 y 4 años), a 83,3 % (13 a 18 años), y en el sexo masculino hubo mayor riesgo de contraer el parásito (razón o cociente de tasas= 0,7). La razón de tasa de Blastocystis spp., según zona de residencia y abasto de agua, fue menor que 1; mientras que, para la tenencia de animales en la casa y el origen del agua para consumo, fue superior a 1. La sintomatología se expresó en 96,6 %, básicamente por dolor abdominal y diarrea. CONCLUSIONES: la infección por Blastocystis spp. de forma única es típica en este estudio de 13 a 18 años, con riesgo incrementado en el sexo masculino, por la tenencia de animales en la casa, consumo de agua sin hervir, zona de residencia urbana y consumo de agua de acueducto. Los principales síntomas corresponden a dolor abdominal y diarrea.

INTRODUCTION: blastocystis spp. is presently considered a possible new intestinal pathogen and its presence is recognized at pediatric ages. OBJECTIVE: to identify the clinical and epidemiological pattern of infection caused by Blastocystis spp. METHODS: descriptive study of 98 patients whose feces were collected at the department of parasitology in "William Soler" pediatric hospital (2008-2009) in Havana. RESULTS: Blastocystis spp. manifested in 59.2 % of cases, significantly higher (p= 0.000) rate than in co-infection (26.7 %) mainly with Giardia lambdia (17.3 %) and Entamoeba histolytica/E. dispar (11.2 %). Regarding infection just by Blastocystis spp. (n= 58), the infection rate rose from 47.2 % (1 and 4 years-old) to 83.3 % (13 to 18 years-old) and males had higher risks of acquiring the parasites (ratio rate= 0.7). The rate ratio of Blastocystisspp., according to the area of residence and water supply system, was lower than 1 whereas having pets at home and origin of the drinking water was over 1. Abdominal pain and diarrheas were the basic symptoms found in 96.6 % of the sample. CONCLUSIONS: single Blastocystis spp. infection is typical in this study in the 13-18 years old group, with increased risk for males, pets at home, taking water that is not boiled, urban area of residence and consumption of tap water. The main symptoms were abdominal pain and diarrheas.

Blastocystis spp: revisión literaria de un parásito intestinal altamente prevalente / Safety conditions at work related to exposure to mechanical hazards in a logistics company - Bogotá 2013

Introducción: Blastocystis spp., se ha identificado como un patógeno emergente causante de diarrea en hombre y en animales. Objetivo: Realizar una revisión sobre las principales características de este parásito y su rol patogénico. Metodología: Se realizó una revisión bibliográfica sobre ciclo de vida, subtipos, epidemiología, y sus posibles factores de virulencia Estas revisiones fueron extraídas de bases de datos como PUBMED, SCIENCE DIRECT, SCIELO, EBSCO y HINARI. Resultados: Blastocystis spp., es de interés por su alta prevalencia en diferentes grupos poblacionales, constante en los estudios epidemiológicos de las parasitosis humanas. Se ha evidenciado en pacientes asintomáticos y en otros con síntomas gastrointestinales, lo que depende del subtipo presente en el portador, sin embargo, esta divergencia se presta para problemas de interpretación. Conclusiones: A pesar de los estudios epidemiológicos, terapéuticos e inmunológicos que se han realizado aún no se tiene claro su ciclo de vida completo, factores de virulencia y patogenicidad.

Introduction: Blastocystis spp., has been identified as an emerging pathogen causing diarrhea in humans and animals. Objective: To conduct a review of the main features of this parasite and its pathogenic role. Methodology: A literature review on the major characteristics of Blastocystis spp., life cycle, subtypes, epidemiology and potential virulence factors was performed Reviews and research articles were extracted from databases such as PUBMED, SCIENCE DIRECT, SCIELO, HINARI and EBSCO. Results: Blastocystis spp. is of interest because of its high prevalence in different population groups, being constant in epidemiological studies of human parasitosis. It has been shown in asymptomatic patients with gastrointestinal symptoms in others, depending on the subtype present in the carrier. However, this difference is due to problems of interpretation. Conclusions: Although epidemiological, therapeutic and immunological studies have been conducted yet, it is not clear its entire life cycle, virulence factors and pathogenicity.

Evidencias y mecanismos de patogenicidad de Blastocystis sp / Evidence and pathogenicity mechanisms of Blastocystis sp

INTRODUCCIÓN: durante las últimas dos décadas se acumularon evidencias que favorecen la aceptación del carácter patógeno de Blastocystis sp. Sin embargo, esos argumentos no son aún del conocimiento de la inmensa mayoría de los profesionales relacionados con el diagnóstico, tratamiento y control de las parasitosis intestinales, en general, y de la blastocistosis, en particular. OBJETIVOS: revisar lo publicado sobre las evidencias en favor de la patogenicidad de Blastocystis sp. y hasta dónde la información acumulada permite exponer los mecanismos por los cuales este parásito puede causar daños en el hospedero humano. MÉTODOS: con el auxilio de diferentes buscadores electrónicos, se realiza una revisión de los artículos sobre patogenicidad de Blastocystis sp. publicados durante el período 1994-2014. Puntualmente, algunas monografías y artículos originales fechados con anterioridad al intervalo mencionado también fueron consultados. CONCLUSIONES: evidencias clínicas, fenotípicas y genotípicas acumuladas durante los últimos tres lustros favorecen la aceptación del carácter patógeno de Blastocystis sp. y estas, una vez difundidas ente los profesionales correspondientes, deberán ser tenidas en cuenta para la realización de un mejor diagnóstico, tratamiento y control de esta parasitosis.

INTRODUCTION: Evidence has been gathered in the past two decades which leads to recognizing the pathogenic nature of Blastocystis sp. However, these arguments are still not known to the vast majority of professionals engaged in the diagnosis, treatment and control of intestinal parasitosis in general and blastocystosis in particular. OBJECTIVES: Review publications containing evidence of the pathogenicity of Blastocystis sp. and determine whether the information accumulated allows description of the mechanisms by which this parasite may cause damage to human hosts. METHODS: Various search engines were used to find and review papers published in the period 1994-2014 dealing with the pathogenicity of Blastocystis sp. Several monographs and original papers dated before the above mentioned period were also consulted. CONCLUSIONS: Clinical, phenotypic and genotypic evidence accumulated in the last fifteen years lead to recognizing the pathogenic nature of Blastocystis sp. Once made known to the corresponding professionals, such evidence should be borne in mind to improve the quality of the diagnosis, treatment and control of this parasitosis.

Subtype Distribution of Blastocystis in Thai-Myanmar Border, Thailand

Blastocystis sp. is a common zoonotic intestinal protozoa which has been classified into 17 subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distribution of Blastocystis in villagers living on the Thai-Myanmar border, where the risk of parasitic infection is high. A total of 207 stool samples were collected and DNA was extracted. PCR and sequencing using primers targeting small-subunit ribosomal RNA (SSU rRNA) gene were performed. The prevalence of Blastocystis infection was 37.2% (77/207). ST3 (19.8%; 41/207) was the predominant subtype, followed by ST1 (11.6%; 24/207), ST2 (5.3%; 11/207), and ST4 (0.5%; 1/207). A phylogenetic tree was reconstructed using the maximum likelihood (ML) method based on the Hasegawa-Kishino-Yano + G + I model. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. Some sequences of Blastocystis positive samples (TK18, 39, 46, 71, and 90) were closely related to animals (pig and cattle) indicating zoonotic risks. Therefore, proper health education in parasitic prevention for the villagers should be promoted to improve their personal hygiene. Further longitudinal studies are required to monitor the prevalence of parasitic infections after providing health education and to investigate Blastocystis ST in animals living in these villages.

Patogenicidad de Blastocystis sp. Evidencias y mecanismos / Pathogenicity of Blastocystis sp. Evidence and mechanisms

Introducción: durante las últimas dos décadas se acumularon evidencias que favorecen la aceptación del carácter patógeno de Blastocystis sp. Sin embargo, esos argumentos no son aún del conocimiento de la inmensa mayoría de los profesionales relacionados con el diagnóstico, tratamiento y control de las parasitosis intestinales, en general, y de la blastocistosis, en particular. Objetivos: revisar lo publicado sobre las evidencias en favor de la patogenicidad de Blastocystis sp. y, hasta dónde la información acumulada permite, exponer los mecanismos por los cuales este parásito puede causar daños en el hospedero humano. Métodos: con el auxilio de diferentes buscadores electrónicos, se realiza una revisión de los artículos sobre patogenicidad de Blastocystis sp. publicados durante el período 1994-2014. Puntualmente, también fueron consultados, algunas monografías y artículos originales fechados con anterioridad al intervalo mencionado. Resultados: se expone y analiza, con un enfoque académico y asistencial, la información actualizada sobre los temas seleccionados. Conclusiones: evidencias clínicas, fenotípicas y genotípicas acumuladas durante los últimos tres lustros favorecen la aceptación del carácter patógeno de Blastocystis sp. y éstas, una vez difundidas ente los profesionales correspondientes, deberán ser tenidas en cuenta para la realización de un mejor diagnóstico, tratamiento y control de esta parasitosis(AU)

Introduction: during the last two decades, evidence supporting the pathogenic character of Blastocystis sp. accumulated. Nevertheless, those arguments are still unknown by the great majority of professionals related with diagnosis, treatment and control of the intestinal infectious in general, and of the blastocystosis in particular. Objectives: to review published materials about pieces of evidence that support the acceptance of the pathogenicity of Blastocystis sp., and to what extent the information accumulated allows revealing the mechanisms by which this parasite causes damage to the human host. Methods: through different search engines, papers about pathogenicity of Blastocystis sp. published during 1994-2014 period were reviewed. Additionally, some monograph and papers dated previously to the mentioned interval were also consulted. Results: updated information about the selected topics, with academic and practical approach, were presented and analyzed. Conclusions: clinical, phenotypic and genetic pieces of evidence accumulated during the last fifteen years support the pathogenic character of Blastocystis sp. Once they are adequately integrated into the practice of the corresponding professionals the diagnosis, treatment and control of blastocystosis could be improved(AU)

Frecuencia y fuentes de Blastocystis sp . en niños de 0 a 5 años de edad atendidos en hogares infantiles públicos de la zona urbana de Calarcá, Colombia / Blastocystis sp . frequency and sources among children from 0 to 5 years of age attending public day care centers in Calarcá, Colombia

Introducción. No se han descrito las fuentes potenciales de infección por Blastocystis sp . en Colombia. Objetivos. Estimar la frecuencia de Blastocystis sp . y explorar posibles asociaciones entre la infección, las manifestaciones clínicas y algunas fuentes ambientales. Materiales y métodos. Se llevó a cabo un estudio descriptivo con una población de 1.993 menores de 5 años (lactantes y preescolares) de estratos socioeconómicos 1 y 2, atendidos en hogares infantiles de Calarcá, Colombia. Se calculó una muestra de 275 y se seleccionó aleatoriamente a los participantes en 10 % de los hogares infantiles. Se practicaron exámenes coprológicos y encuestas y se tomaron muestras para la identificación del parásito en heces, uñas, animales domésticos y algunas fuentes ambientales. Se hicieron preparaciones en fresco con lugol al 1 % y se utilizó una técnica de concentración con formol-éter. Se estimaron prevalencias y razones de momios; para las variables cualitativas se utilizó el test de ji al cuadrado y, para las cuantitativas, la prueba t de Student. Resultados. La prevalencia de infección en los niños fue de 57,5 %. Hubo asociación estadísticamente significativa entre la presencia del parásito en heces y su hallazgo en recipientes de agua de panela (OR=1,70; IC 95% 1,05-2,79), en los pisos de madera o de tierra en la vivienda (OR=3,43; IC 95% 1,12-10,48), y en alimentos diferentes a la leche en el tetero (OR=3,23; IC 95% 1,41-4,41); y se encontró una prevalencia alta sin asociación en muestras de uñas (OR=1,62; IC 95% 0,99-2,67). La diarrea fue más frecuente en niños con Blastocystis sp. (45 %) que en aquellos sin el parásito (33 %) (OR: 1,95; IC 95% 0,99-2,77) (p<0,05). Conclusiones. Blastocystis sp . se asoció significativamente con síntomas de diarrea en los niños menores de 5 años y se encontró distribuido ampliamente en el ambiente y en el agua. Se requeriría determinar si hay huéspedes específicos para genotipos patógenos por medio de técnicas moleculares.

Introduction: There are no reports of the potential sources of Blastocystis sp . in Colombia. Objectives: To estimate the frequency of Blastocystis sp . and explore possible associations among infection, clinical manifestations and environmental sources. Materials and methods: A descriptive study was conducted; a representative sample was calculated from a population of 1,993 children less than 5 years old of the lowest socioeconomic levels (1 and 2) attending day care centers in Calarcá, Colombia. The calculated sample size was 275 children, who were selected randomly in 10 % of the centers. Stool testing, questionnaires and sampling to identify the parasite in feces, nails, pets and environmental sources, were performed. Fresh preparations were made with 1% iodine solution, and a concentration technique with formalin-ether was used. Prevalence and odd ratios were estimated; the chi-square test was utilized for qualitative variables, and Student´s t for the quantitative ones. Results: The prevalence of infection in children was of 57.5%. A statistically significant association was found between the Blastocystis sp . positive stool tests and the presence of the parasite in containers of sugar cane beverage (OR=1.70; 95% CI: 1.05-2.79), wood or ground floors (OR=3.43; 95% CI: 1.12-10.48) and in foods other than bottled milk (OR=3.23; 95% CI: 1.41-4.41) . A non-significant high prevalence was found in nails (OR=1.62; 95% CI: 0.99-2.67), as well as a significantly higher prevalence of diarrhea (OR=1.95; 95% CI: 0.99-2.77) in children with Blastocystis sp . (45%) as compared with those without the parasite (33%; p<0.05). Conclusions: Blastocystis sp . showed a significant association with diarrhea symptoms in children 0 to 5 years old and was widely distributed in the environment and in water. It is necessary to determine if there are specific hosts with pathogenic potential through molecular techniques.

Epidemiological and diagnostic features of blastocystis infection in symptomatic patients in Izmir province, Turkey

The aims of this study were to identify Blastocystis subtypes [STs] in a cohort of Turkish patients with various gastrointestinal symptoms using a novel Real Time PCR method developed recently for Blastocystis detection and assess the relationship between Blastocystis STs and patient symptoms. Totally, 617 stool samples of patients with gastrointestinal symptoms were examined with microscopy and inoculated in Jones medium. Blastocystispositive samples were further assessed to identify coinfections with other possible pathogens, including bacteria and viruses. Diagnostic efficacies of microscopy, culture and Real-Time PCR were compared. PCR products were sequenced to identify the subtypes of Blastocystis isolates. Totally 94 [15.24%] samples were positive for Blastocystis after all methods. Among these, 83 of 94 [88.3%] samples were identified with all methods, while 11 were positive only with Real Time PCR. Diarrhea and abdominal pain were the leading symptoms in the patients. The only pathogenic agent identified in 76 of 94 [80.9%] patients was Blastocystis. Subtype 3 was the leading Blastocystis subtype [44.6%], while subtypes 6 and 7 were firstly isolated from symptomatic patients in our region. Comparison of three diagnostic methods indicated Real Time PCR as the most sensitive and specific method. Blastocystis was the only pathogenic agent among symptomatic patients, with subtype 3 being predominant. Patients with subtypes 6 and 7 need further assessments concerning the zoonotic potential of Blastocystis