Dinámica de la evolución de las formas de Blastocystis spp. en un medio de cultivo simple / Dynamics of the evolution of the forms of Blastocystis spp. in a simple culture medium

Resumen Blastocystis spp. es un parásito muy frecuente en materia fecal humana, pero la naturaleza polimórfica y el número de Blastocystis en la muestra pueden complicar su detección por microscopía. El objetivo del trabajo fue describir la dinámica de los morfotipos de Blastocystis a corto plazo en un medio de cultivo simple y determinar su aplicabilidad para utilizarlo como complemento del análisis coproparasitológico y para estudios morfológicos, bioquímicos y moleculares del parásito. Se sembraron 10 muestras de materia fecal con Blastocystis en un medio Pavlova adaptado, se examinaron diariamente por examen microscópico durante 6 días y se registraron las formas y el recuento. El desarrollo fue regular y abundante y las formas fueron de tamaños variables y claramente identificables. El cultivo ensayado puede ser útil para la detección de Blastocystis cuando existan dudas diagnósticas por microscopía, para estudios de sensibilidad y especificidad diagnóstica o cuando se requiera aumentar la carga para realizar otros estudios.

Abstract Blastocystis spp. is a very frequent parasite in human fecal matter, but the polymorphic nature and the number of Blastocystis in a sample can complicate its detection by microscopy. The objective of the present work was to describe the dynamics of Blastocystis morphotypes in the short term in a simple culture medium and to determine its applicability to use it as a complement to coproparasitological analysis and for morphological, biochemical and molecular studies of the parasite. Ten stool samples with Blastocystis were cultured in an adapted Pavlova medium and examined during 6 days by microscopy to record the forms and the count. The development was regular and abundant and the shapes were of variable sizes and clearly identifiable. The tested culture could be used for the detection of Blastocystis when microscopic diagnosis is dubious, for studies of diagnostic sensitivity and specificity or when it is necessary to increase the load to perform other studies.

Resumo Blastocystis spp. é um parasita muito frequente nas fezes humanas, mas a natureza polimórfica e o número de Blastocystis na amostra podem complicar a sua detecção através do microscópio. O objetivo do trabalho foi descrever a dinâmica dos morfotipos de Blastocystis no curto prazo em um meio de cultura simples e determinar sua aplicabilidade para ser utilizado como complemento da análise coproparasitológica e para estudos morfológicos, bioquímicos e moleculares do parasita. Foram semeadas dez amostras de fezes com Blastocystis em um meio Pavlova adaptado e examinadas diariamente através de exame microscópico durante 6 dias, registrando as formas e fazendo recontagem. O desenvolvimento foi regular e abundante e as formas foram de tamanhos variáveis e claramente identificáveis. A cultura testada pode ser útil para a detecção de Blastocystis quando houver dúvidas diagnósticas por microscopia; para estudos de sensibilidade e especificidade diagnóstica ou quando for necessário aumentar a carga para a realização de outros estudos.

Standardization of molecular techniques for the detection and characterization of intestinal protozoa and other pathogens in humans

Background: The intrinsic sensitivity limitations of basic parasitological methods, along with the particular biological characteristics of parasites, make these methods ineffective to differentiate morphologically indistinguishable species. Molecular detection and characterization techniques could be used to overcome these problems. The purpose of this work was to standardize molecular polymerase chain reaction (PCR) techniques, described in the literature, for the detection and molecular characterization of intestinal protozoa and other pathogens in humans. Methods: DNA was extracted from human or animal feces, previously washed or cultured in Boeck Drbohlav's Modified Medium. DNA extraction was performed with Machery-Nagel extraction kits. The standardization of the PCR, nested-PCR or RFLP techniques was carried out according to the literature. For each molecular technique performed, the sensitivity of the test was determined based on the minimun quantity required of DNA (sensitivity A) and the minimum quantity of life forms that the test detected (sensitivity B). Results: Sensitivity A was 10 fg for G. duodenalis, 12.5 pg for Entamoeba histolytica or Entamoeba dispar, 50 fg for Cryptosporidium spp., 225 pg for Cyclospora spp. and 800 fg or 8 fg for Blastocystis spp. after performing a 1780 bp PCR or 310 bp nested PCR, respectively. The sensitivity B was 100 cysts for G. duodenalis, 500 cysts for E. histolytica or E. dispar, 1000 oocysts for Cyclospora spp. and 3600 or four vegetatives forms for PCR or nested PCR of Blastocystis spp., respectively. Conclusions: The molecular detection of protozoa and chromist was achieved and the molecular characterization allowed the genotyping of some of the parasites such as Giardia duodenalis, Cryptosporidium spp., and Blastocystis spp. This study summarizes the molecular techniques for epidemiological studies in humans and animals, and helps in the investigation of their transmission sources in countries where intestinal parasites are a public health problem.(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)

Blastocystis: estudio coproparasitológico, clínico-epidemiológico y de prevalencia de subtipo 3 en pacientes de hospitales de Bahía Blanca, Argentina / Blastocystis: coproparasitological, clinical-epidemiological and prevalence study of subtype 3 in patients from hospitals in Bahía Blanca, Argentina

Resumen Blastocystis es el parásito unicelular del intestino del hombre y de otros animales más prevalente en seres humanos. Presenta gran variedad genética con múltiples subtipos (ST). Aunque se ha asociado a desórdenes intestinales y extraintestinales, su patogenicidad es discutida. Se analizaron 461 muestras de materia fecal de pacientes sintomáticos (n=380) y asintomáticos (n=81) de hospitales de Bahía Blanca, Argentina; se solicitó consentimiento informado y se completó una ficha epidemiológica. Se realizaron análisis coproparasitológicos, morfometría, recuento y tipificación de Blastocystis ST3 por PCR. La población fue: 57,3% de sexo femenino y 42,7% masculino. La prevalencia de Blastocystis fue de 31% y de Blastocystis ST3 62%. Se hallaron formas vacuolares, granulares y quísticas; las vacuolares fueron las más frecuentes. En el 64,8% de las muestras los Blastocystis fueron pequeños y escasos. El 88,4% de los pacientes sintomáticos presentó trastornos gastrointestinales, el 4% urticaria y el 7,6% fiebre, anemia y bajo peso. El 66,7% de los pacientes con urticaria presentó Blastocystis. La presencia de síntomas se asoció significativamente con Blastocystis (p<0,002). No se hallaron asociaciones estadísticas entre Blastocystis, la edad, el sexo, la disponibilidad de agua potable, de cloacas y el contacto con animales. Dentro de los síntomas sólo se encontró asociación estadística de Blastocystis con urticaria (p<0,007). No hubo asociación entre Blastocystis ST3 y sintomatología. Los resultados destacan la alta prevalencia de Blastocystis y de Blastocystis ST3, la necesidad de hacer un coproparasitológico minucioso, su asociación estadística con urticaria y la importancia de no ignorarlo en el proceso salud-enfermedad.

Abstract Blastocystis is the unicellular parasite of the intestine of man and other animals,most prevalent in humans. It has a great genetic variety with multiple subtypes (ST). Although it has been associated with intestinal and extraintestinal disorders, its pathogenicity remains unclear. Four hundred and sixty one stool samples from symptomatic (n=380) and asymptomatic(n=81) patients from hospitals in Bahía Blanca, Argentina were analysed; informed consent was requested and an epidemiological file was completed. Coproparasitological analysis, morphometry, counting and typing of Blastocystis ST3 were performed by PCR. The population was: 57.3% female and 42.7% male.The prevalence of Blastocystis was 31.0% and that of Blastocystis ST3 62%. Vacuolar, granular and cystic forms were found, with vacuolar forms being the most frequent. Blastocystis were small and scarce in 64.8% of the samples. Most of the symptomatic patients (88.4%) presented gastrointestinal disorders, urticaria 4% and fever, anemia and low weight 7.6%; 66.7% of the urticaria patients presented Blastocystis. The presence of symptoms was significantly associated with Blastocystis (p<0.002). No statistical associations were found between Blastocystis, age, sex, availability of drinking water, sewage, and contact with animals. Within the symptoms, only statistical association of Blastocystis with urticaria was found (p<0.007). There was no association between Blastocystis ST3 and symptomatology. The results highlight the high prevalenceof Blastocystis and Blastocystis ST3, the need for a thorough coproparasitology, their statistical association with urticaria and the importance of not ignoring it in the health-disease process.

Resumo Blastocystis é o parasita unicelular do intestino do homem e outros animais, mais prevalente em seres humanos. Apresenta grande variedade genética com múltiplos subtipos (ST). Embora tenha sido associada a distúrbios intestinais e extraintestinais, sua patogenicidade é debatida. Foram analisadas 461 amostras de fezes de pacientes sintomáticos (n=380) e assintomáticos (n= 81) de hospitais de Bahía Blanca, Argentina; foi solicitado consentimento informado e preenchida uma ficha epidemiológica. Foram realizadas análises coproparasitológicas, morfometria, contagem e tipificação de Blastocystis ST3 por PCR. A população era: 57,3% sexo feminino e 42,7% masculino. A prevalência de Blastocystis foi de 31,0% e de Blastocystis ST3 62%. Foram encontradas formas vacuolares, granulares e císticas, sendo as vacuolares as mais frequentes. Em 64,8% das amostras, os Blastocystis foram pequenos e escassos; 88,4% dos pacientes sintomáticos apresentaram distúrbios gastrointestinais, 4% urticária e 7,6% febre, anemia e baixo peso; 66,7% dos pacientes com urticária apresentaram Blastocystis. A presença de sintomas foi associada significativamente com Blastocystis (p˂0,002). Não foram encontradas associações estatísticas entre Blastocystis, a idade, sexo, a disponibilidade de água potável, de esgoto e o contato com animais. Dentro dos sintomas, só foi encontrada associação estatística de Blastocystis com urticária (p˂0,007). Não houve associação entre Blastocystis ST3 e sintomatologia. Os resultados destacam a alta prevalência de Blastocystis e Blastocystis ST3, a necessidade de fazer um coproparasitologico minucioso, sua associação estatística com urticária e a importância de não ignorá-lo no processo saúde-doença.

Infección por Blastocystis spp. en individuos inmunocompetentes e inmunocomprometidos / Blastocystis spp. Infection in immunocompetent and immunocompromised individuals

Blastocystis spp. es un parásito controversial que ha sufrido múltiples reclasificaciones y cuyo rol patógeno para el hombre sigue siendo incierto. Para relacionar la presencia de Blastocystis spp. en pacientes inmunocompetentes e inmunocomprometidos, en ausencia o presencia de sintomatología, se evaluó la morfometría y número de parásitos en individuos procedentes del Servicio Autónomo Hospital Universitario "Antonio Patricio de Alcalá" municipio Sucre, estado Sucre, previo consentimiento informado, durante los meses septiembre a diciembre de 2018. Cada espécimen fecal fue analizado mediante examen directo, la semi-cuantificación del cromista se hizo en diez campos consecutivos de 40X, el análisis morfométrico mediante frotis fecales teñidos con Giemsa observados a 100X y micrometría. Del total de pacientes evaluados (n=162), el cromista ocupó el primer lugar de prevalencia en inmunocompetentes (32,86%), del grupo de inmunocomprometidos los más afectados fueron los desnutridos (8,02%), seguido de los oncológicos y con infección por VIH/SIDA con 5,56% y 1,85% respectivamente. En ambos grupos las manifestaciones clínicas más comunes dolor abdominal, diarrea y flatulencia; con respecto a la cuantificación, se pudo evidenciar que un pequeño grupo de pacientes oncológicos y con desnutrición que presentaban sintomatología, tenían contajes inferiores a 5 parásitos por campo. Al realizar el análisis morfométrico, la forma de cuerpo central fue la única identificada en ambos grupos, coincidiendo con los resultados obtenidos en el examen directo, los morfotipos evaluados presentaron diámetros >10 µm, siendo de mayor diámetro en pacientes inmunocomprometidos que en inmunocompetentes (p<0,05)

Blastocystis spp. it is a controversial parasite that has undergone multiple reclassifications and whose pathogenic role for man remains uncertain. To relate the presence of Blastocystis spp. in immunocompetent and immunocompromised patients, in the absence or presence of symptoms, morphometry and number of parasites in individuals were evaluated, from the of the University Hospital "Antonio Patricio de Alcalá", Cumaná, Sucre state, with prior informed consent, during the months September to December 2018. Each fecal specimen was analyzed by direct examination, the semi-quantification of the chromist was done in ten consecutive fields of 40X, the morphometric analysis by means of fecal smears stained with Giemsa observed at 100X and micrometry. Of the total number of patients evaluated (n = 162), the chromist ranked first in prevalence in immunocompetent (32.86%), of the immunocompromised group the most affected were malnourished patients (8.02%), followed by oncological and with HIV/AIDS infection with 5.56% and 1.85% respectively. In both groups, symptomatic patients were presented, the most common clinical manifestations being abdominal pain, diarrhea and flatulence; with respect to quantification, it was possible to show that a small group of cancer patients with malnutrition who presented symptoms had counts of less than 5 parasites per field. When performing the morphometric analysis, the central body shape was the only one identified in both groups, coinciding with the results obtained in the direct examination, the evaluated morphotypes presented diameters >10 µm, being larger in immunocompromised patients than in immunocompetent patients (p <0.05)

Prevalencia de parásitos intestinales en niños preescolares del municipio Angostura del Orinoco, estado Bolívar, Venezuela. 2016-2018 / Prevalence of intestinal parasites in preschool children from the Angostura del Orinoco municipality, Bolívar state, Venezuela. 2016-2018

El objetivo de la presente investigación fue determinar la prevalencia de parásitos intestinales en niños preescolares usuarios de 12 Centros de Educación Inicial Simoncito (CEIS) del municipio Angostura del Orinoco, estado Bolívar, Venezuela. Se estudiaron las heces de 515 niños de ambos géneros (2 a 5 años), mediante la técnica de sedimentación espontánea. La prevalencia de enteroparásitos fue de 39,4% (n=203). No hubo diferencias estadísticamente significativas (χ2 = 1,59 g.l.: 2 p> 0,05) respecto a la edad, pero si según el género (p<0,05), resultando los niños varones más afectados con 46,9%. Se identificaron 11 taxones de enteroparásitos, destacando el cromista Blastocystis spp. con 27,4% (n=141) y el protozoario Giardia intestinalis con 13,2% (n=68). Se encontró una baja prevalencia de helmintos, donde Ascaris lumbricoides fue el más común con 1,6% (n=8). De los 203 niños parasitados, el 70,9% (n=144) estaba monoparasitado y 29,1% (n=59) poliparasitado. Los principales parásitos asociados fueron Blastocystis spp. (89,8%), G. intestinalis (44,1%) y Endolimax nana (35,3%). En conclusión, se determinó una elevada prevalencia de parásitos intestinales en la población estudiada, por lo que estas infecciones continúan siendo un problema de salud pública en niños de Ciudad Bolívar, Venezuela

The objective of the present investigation was to determine the prevalence of intestinal parasites in preschool children users of 12 Simoncito Initial Education Centers (CEIS) of the Angostura del Orinoco municipality, Bolívar state, Venezuela. The feces of 515 children of both genders (2 to 5 years old) were studied using the spontaneous sedimentation technique. The prevalence of enteroparasites was 39.4% (n = 203). There were no statistically significant differences (χ2 = 1.59 d.f .: 2 p> 0.05) with respect to age but if according to gender (p <0.05), because the most affected were male child with 46.9%. Eleven taxa of enteroparasites were identified, highlighting the chromist Blastocystis spp. (27.4%) and the protozoan Giardia intestinalis (13.2%). A low prevalence of helminths was found, where Ascaris lumbricoides was the most common with 1.6%. Of the 203 parasitized children, 70.9% (n = 144) were monoparasitized and 29.1% (n = 59) polyparasitized. The main associated parasites were Blastocystis spp. (89.8%), G. intestinalis (44.1%) and Endolimax nana (35.3%). In conclusion, a high prevalence of intestinal parasites was determined in the population studied, so these infections continue to be a public health problem in children from Ciudad Bolívar, Venezuela

Occurrence of Blastocystis spp. in domestic animals in Triângulo Mineiro area of Brazil

Abstract INTRODUCTION: Currently, there are few studies regarding Blastocystis epidemiology. This study aimed to evaluate the occurrence of Blastocystis in animals in Uberaba, Brazil. METHODS: Fecal samples were examined by parasitological methods and screened for Blastocystis by polymerase chain reaction. RESULTS: Blastocystis spp. were observed in pigs, sheep, cattle, and dogs. Blastocystis polymerase chain reaction was positive in 14/22 samples positive by parasitological methods. CONCLUSIONS: The occurrence of Blastocystis in animals is high, with a predominance of subtype 1 in the region. This is the first study conducted in Brazil showing the genetic profile of Blastocystis isolated from animals.

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.

Prevalencia de enteroparasitos en individuos seropositivos y seronegativos a los virus HTLV-I/II

Para determinar la prevalencia de enteroparásitos en individuos seropositivos a los virus HTLV-I/II, se seleccionaron aleatoriamente 75 donantes que asistieron a los Bancos de Sangre de dos instituciones sanitarias del municipio Maracaibo, Venezuela. Se contactaron personalmente 50 individuos seropositivos a virus HTLV-I/II (grupo muestra) y 25 seronegativos (grupo control), quienes aportaron una muestra fecal para diagnóstico parasitológico. Estas fueron sometidas al examen al fresco con solución salina fisiológica (SSF) al 0,85%, tinción temporal de Lugol y técnica de concentración con formol-éter (Ritchie). Además se realizó cultivo en Agar Nutritivo (método de Arakaki) para investigar la presencia de larvas de Strongyloides stercoralis. Se determinó una prevalencia general de enteroparásitos en el grupo muestra de 54% y 44% en el grupo control. Predominó el monoparasitismo entre todos los individuos estudiados. Las especies identificadas fueron: Blastocystis spp. 47,3% y 15,4%, Entamoeba coli 21% y 15,4%, Endolimax nana 13% y 53,8%, Complejo Entamoeba 10,5% y 15,4%, Giardia intestinalis 5,2% y 0%, y Entamoeba hartmanni 2,6% y 0% en el grupo muestra y grupo control, respectivamente. No se detectó Strongyloides stercoralis ni otros helmintos intestinales, en los individuos estudiados. Blastocystis spp. fue el más frecuente en los pacientes seropositivos (diferencia estadísticamente significativa) que en el grupo control, lo que pudiese relacionarse con una mayor persistencia de este cromista en pacientes coinfectados con HTLV-I/II. Se puede concluir que el estatus serológico del individuo HTLV-I/II positivo parece no influir en la presencia o adquisición de parásitos intestinales.

Prevalence of intestinal parasites in seropositive and seronegative to HTLV I/II viruses

The prevalence of intestinal parasites in individuals seropositive for the HTLV-I/II virus was studied. A total of 75 donors who attended the blood banks of two health institutions in Maracaibo, Venezuela were randomly selected: 50 patients seropositive for HTLV-I/II (study group) and 25 seronegative individuals (control group). The participants in the study were all contacted personally, after which they provided a fecal sample for parasitological diagnosis. The fresh samples were examined using 0.85% physiological saline solution (PSS), Lugol’s solution for temporary staining and the formalin-ether concentration technique (Ritchie). In addition, samples were cultured on nutrient agar (Arakaki method) to determine the presence of Strongyloides stercoralis larvae. Overall prevalences of 54% intestinal parasites in the study group and 44% in the control group were found. Monoparasitism prevailed among all the individuals studied. The species identified in the study and control groups were: Blastocystis spp. 47.3% and 15.4%, Entamoeba coli 21% and 15.4%, Endolimax nana 13.0% and 53.8%, Entamoeba complex 10.5% and 15.4%, Giardia intestinalis 5.2% and 0%, and Entamoeba hartmanni 2.6% and 0 %, respectively. Strongyloides stercoralis and other intestinal helminths were not detected in the individuals studied. Blastocystis spp. was significantly more common in seropositive patients than in the control group, which could be associated with a greater persistence of this chromista in patients co-infected with HTLV-I / II.It can be concluded that the positive serological status of HTLV-I / II infected individuals does not seem to influence either the presence or acquisition of intestinal parasites.

Prevalencia de parásitos intestinales en escolares de Ciudad Bolívar, Venezuela: comparación entre dos períodos / Prevalence of intestinal parasites in school children from Ciudad Bolívar, Venezuela: comparison between two periods

Se determinó la prevalencia de parásitos intestinales en 921 escolares de 9 escuelas de Ciudad Bolívar, estado Bolívar, Venezuela durante el período 2009-2013 y se comparó con la obtenida en la misma ciudad en el período 1995-1996, en 7 escuelas y 446 niños. En la primera oportunidad las muestras fecales fueron analizadas mediante examen directo y técnica de Willis; mientras que para la segunda, las heces fueron sometidas al directo, Kato y sedimentación espontánea. La prevalencia general de enteroparásitos para los períodos 1995-1996 y 2009-2013 fue de 52% y 62,9% respectivamente. En el primer período prevalecieron los helmintos y para el segundo el grupo de Chromistas-Protozoarios resulto más prevalente. Para 1995-1996, los helmintos Trichuris trichiura (24,2%) y Ascaris lumbricoides (19,5%) resultaron más comunes; mientras que para el período 2009- 2013, el chromista Blastocystis fue el más prevalente (47,6%), seguido del protozoario Endolimax nana (17,7%). En todos esos casos la diferencia fue significativa (p<0,05) cuando se comparan las prevalencias de ambos períodos. Se concluye que hubo un cambio en la prevalencia de los parásitos intestinales en la población evaluada: en el primer período (1995-1996) predominaron los helmintos y para el segundo (2009-2013) el chromista Blastocystis spp. y los protozoarios.

The prevalence of intestinal parasites in 921 schoolchildren from nine schools in Ciudad Bolivar, Bolivar State, Venezuela during the period 2009-2013 was determined and compared with that obtained in the same city in the period 1995-1996 in seven schools and 446 children. At the first opportunity the fecal samples were analyzed by direct examination and Willis technical; while for the second, feces were submitted to direct, Kato and spontaneous sedimentation. The overall prevalence of intestinal parasites for the periods 1995-1996 and 2009-2013 was 52% and 62.9% respectively. In the first period, the helminths prevailed and the second, the Chromistas-Protozoa group turned more prevalent. For 1995-1996, the helminths Trichuris trichiura (24.2%) and Ascaris lumbricoides (19.5%) were more common; while for the period 2009-2013, the Chromista Blastocystis spp. was the most prevalent (47.6%), followed by protozoan Endolimax nana (17.7%). In all these cases the difference was significant (p <0.05) when the prevalence of both periods being compared. We conclude that there was a change in the prevalence of intestinal parasites in the study population: in the first period (1995-1996) dominated the helminths and the second (2009-2013) the Chromista Blastocystis spp. and protozoa.

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.

OCCURRENCE OF Blastocystis spp. IN UBERABA, MINAS GERAIS, BRAZIL / Ocorrência de Blastocystis spp. em Uberaba, Minas Gerais, Brasil

Intestinal parasites are a problem for public health all over the world. The infection with Blastocystis, a protozoan of controversial pathogenicity, is one of the most common among them all. In this study, the occurrence of intestinal parasites, with emphasis on Blastocystis, in patients at the Universidade Federal do Triângulo Mineiro was investigated in Uberaba (MG) through microscopy of direct smears and fecal concentrates using Ritchie’s method. Feces of 1,323 patients were examined from April 2011 to May 2012. In 28.7% of them at least one intestinal parasite was identified, and the most frequent organisms were Blastocystis spp. (17.8%) and Giardia intestinalis (7.4%). The occurrence of parasitism was higher in children aged 6 -10 years old, and the infection with Blastocystis spp. was higher above the age of six (p < 0.001). The exclusive presence of G. intestinalis and of Blastocystis spp. was observed in 5.4% and 12.2% of the patients, respectively. Regarding patients with diarrheic feces, 8% revealed unique parasitism of Blastocystis spp. Other intestinal parasites observed in children were Ascaris lumbricoides (0.3%) and Entamoeba histolytica/dispar/moshkovskii (1.4%). The Ritchie’s method was more sensitive (92.8%) when compared to direct microscopy (89.8%), with high agreement between them (97.7%, kappa = 0.92). In conclusion, the occurrence of Blastocystis spp. in Uberaba is high and the presence of diarrheic feces with exclusive presence of the parasite of Blastocystis spp. was observed.

Parasitos intestinais são um problema de saúde pública no mundo e a infecção por Blastocystis, protozoário de patogenicidade controversa, é uma das mais frequentes. Nesse estudo foi investigada a ocorrência de parasitos intestinais em pacientes atendidos na Universidade Federal do Triângulo Mineiro, em Uberaba (MG), com ênfase em Blastocystis, pelos métodos parasitológicos direto e de Ritchie. Foram examinadas fezes de 1.323 pacientes de abril/2011 a maio/2012. Em 28,7% deles foi identificado um parasito intestinal, sendo Blastocystis spp. (17,8%) e Giardia intestinalis (7,4%) os mais frequentes. A ocorrência de parasitismo foi maior em crianças de 6-10 anos e a infecção por Blastocystis spp. foi maior acima de seis anos (p < 0,001). Presença exclusiva de G. intestinalis e de Blastocystis spp. foi observada em 5,4% e 12,2% dos pacientes, respectivamente, sendo que dos pacientes com fezes diarreicas, 8% apresentavam parasitismo exclusivo por Blastocystis spp. Outros parasitos intestinais observados em crianças foram Ascaris lumbricoides (0,3%) e Entamoeba histolytica/dispar/moshkovskii (1,4%). O método de Ritchie foi mais sensível (92,8%) que o direto (89,8%), com alta concordância entre eles (97,7%, kappa = 0,92). Em conclusão, a ocorrência de Blastocystis spp. em Uberaba é elevada e foi observada a presença de fezes diarreicas com parasitismo exclusivo por Blastocystis spp.

Prevalencia de parásitos intestinales en habitantes de una comunidad rural del estado Bolívar, Venezuela / Prevalence of Intestinal Parasites in Residents from a Rural Community in the State of Bolivar, Venezuela

Determinar la prevalencia de parásitos intestinales en una muestra de habitantes de la comunidad rural “La Carolina” del estado Bolívar, Venezuela. Materiales y Métodos: Una muestra fecal de cada habitante participante fue analizada mediante las técnicas de examen directo, Kato, Sedimentación Espontánea y coloración de Kinyoun. Resultados: De los 115 habitantes evaluados, 97 resultaron parasitados para una prevalencia de 84,3%. Con relación a la edad, todos los grupos fueron afectados por igual ( =0,812 g.l.: 6 p>0,05) aunque la mayor cantidad de casos (52 habitantes) se encontraron en el grupo de 0-9 años. Ambos sexos fueron afectados por igual (p>0,05). Se encontró 54,6% de poliparasismo y 45,4% de monoparasitismo. Nueve especies de enteroparásitos fueron diagnosticados, siendo el grupo de los chromistas y protozoarios más prevalentes (94,8%) que los helmintos. Blastocystis spp. fue el parásito más prevalente con 65,2%. No se diagnosticaron coccidios intestinales. Las asociaciones parasitarias más comunes fueron entre protozoarios, destacándose la de Blastocystis spp con Giardia intestinalis (22,6%) y Blastocystis spp. con Endolimax nana (15,1%). Conclusión: Se determinó una importante prevalencia de parásitos intestinales (84,3%) en la comunidad rural “La Carolina” del estado Bolívar, Venezuela.

To determine the prevalence of intestinal parasites in a sample of residents from the rural community, “La Carolina,” in the State of Bolivar, Venezuela. Material and Methods: A fecal sample from each participating inhabitant was analyzed using techniques of direct examination, Kato, spontaneous sedimentation and Kinyoun staining. Of the 115 people tested, 97 were parasitized with a prevalence of 84.3 %. With regard to age, all groups were affected equally (² = 0.812 df: 6 p > 0.05), although the largest number of cases (52 people) were found in the group of 0-9 years. Both sexes were equally affected (p> 0.05). The study found 54.6% polyparasitism and 45.4% monoparasitism. Nine species of intestinal parasites were diagnosed. The group of protozoa and chromists were more prevalent (94.8%) than helminths. Blastocystis spp. was the most prevalent parasite with 65.2 %. No intestinal coccidia were diagnosed. The most common parasitic associations were between protozoa, emphasizing Blastocystis spp. with Giardia intestinalis (22.6%) and Blastocystis spp. with Endolimax nana (15.1%). An important prevalence of intestinal parasites (84.3%) was determined in the rural community, “La Carolina,” State of Bolivar.