Establishment of Blastocystis hominis in-vitro Culture Using Fecal Samples from Infants in Slum Area of Mirpur, Dhaka, Bangladesh.

Introduction: Blastocystis hominis (B. hominis) is an obligate anaerobic protozoan found in the human large intestine, and is the most common eukaryotic organism reported in human fecal samples. Method: Multiple stool samples from 460 children (53.9% male and 46.07% female) were collected and examined for the presence of Blastocystis hominis in Parasitology Laboratory of International Centre for Diarrhoeal Diseases Research, Bangladesh during the period of 9th January to 28th December, 2011. Among them, 255 were diarrheal patients (56.47% male and 43.53% female). Direct microscopy was done for each of the samples and each sample was cultured in vitro for 48 hours and observed again for the presence of the pathogen. Th e aim of the study was to develop a sustainable technique to identify the pathogen. Results: In culture, several morphological forms were observed. Th rough microscopy, various morphological forms were clearly observed. Within 5679 tested samples, 795 samples (0.14%) were positive for B. hominis. As multiple forms were observed in the same sample, the most prevalent was cyst (0.125%) whereas least prevalent was granular (0.0072%). Th e highest percentage for all the morphological forms was observed in age group 25-36 months. In direct microscopy from fresh samples, children from 37-48 months showed the highest percentage (22.9%) of infection (p=0.000). In culture, the same age group showed the most infection rate (p=0.000). Among the diff erent morphological forms observed in culture, the highest prevalence of cyst was in age group 37-48 months (p=0.000). Th e highest prevalence of vacuolar form(5.7%) was observed in the same age group (p=0.015). In contrast, the amoeboid forms were mostly observed in children of 25-36 months (p=0.002).Th e children aged in between 37 to 48 months are at the most risk of the infection. Conclusion: Th e sensitivity of direct microscopy was found only 38.46% in respect to in-vitro culture which strongly suggests that in-vitro culture is the gold standard for the diagnosis of this parasite.

Padronização do diagnóstico de Blastocystis hominis por diferentes técnicas de coloração / Standardization of Blastocystis hominis diagnosis using different staining techniques

INTRODUÇÃO: O presente trabalho foi realizado no período de março a maio de 2008, com o objetivo de avaliar a eficácia de diferentes técnicas para diagnóstico de Blastocystis hominis em uma amostra da população atendida pelo Laboratório de Biomedicina da Universidade Feevale, Novo Hamburgo/RS. MÉTODOS: Foram estudadas 100 amostras de fezes de crianças e adultos, que foram coletadas e submetidas às técnicas de sedimentação espontânea (HPJ), sedimentação em formol-éter (Ritchie) e de coloração por Gram e May-Grünwald-Giemsa (MGG). RESULTADOS: A presença de Blastocystis hominis foi observada em 40 amostras, quando utilizadas técnicas de coloração (MGG e Gram), enquanto que as técnicas de sedimentação se mostraram menos eficientes (32 amostras positivas para a técnica de Ritchie e 20 amostras positivas para a técnica de HPJ). CONCLUSÕES: Nossos resultados demonstram que o HPJ foi menos eficiente que outros métodos, indicando a necessidade de se incluir na rotina do laboratório técnicas que permitam a identificação deste parasita.

INTRODUCTION: The present study was carried out from March to May 2008, with the aim of evaluating the effectiveness of different techniques for diagnosing Blastocystis hominis in a sample of the population attended at the Biomedicine Laboratory of Feevale University, Novo Hamburgo, Rio Grande do Sul. METHODS: On hundred feces samples from children and adults were evaluated. After collection, the samples were subjected to the techniques of spontaneous sedimentation (HPJ), sedimentation in formalin-ether (Ritchie) and staining by means of Gram and May-Grünwald-Giemsa (MGG). RESULTS: The presence of Blastocystis hominis was observed in 40 samples, when staining techniques were used (MGG and Gram), while sedimentation techniques were less efficient (32 positive samples using the Ritchie technique and 20 positive samples using the HPJ technique). CONCLUSIONS: Our results demonstrate that HPJ was less efficient than the other methods, thus indicating the need to include laboratory techniques that enable parasite identification on a routine basis.

Transición parasitaria a Blastocystis hominis en niños de la zona centro del estado de Guerrero, México / Parasitic transition to Blastocystis hominis in children from center zone of Guerrero state, Mexico

Blastocystis hominis es un organismo emergente cuya prevalencia se ha incrementado en los últimos años. La frecuencia en México va de 4,0 por ciento a 62 por ciento, sin reportes previos en el estado de Guerrero. La población estudiada fueron tres localidades del estado de Guerrero: Chilpancingo, Petaquilla y Tixtla en un total de 1.138 niños preescolares y escolares, de ambos sexos. Mediante tres técnicas coproparasitóscopicas (CPS): examen directo, concentración por flotación de Faust y cultivo de Barret, se detectaron un total de 38 por ciento de niños parasitados y B. hominis ocupó el primer lugar con el 61 por ciento de los CPS positivos. El 90 por ciento de los casos fueron parasitosis única. El 58 por ciento de los niños aparentemente sanos y con B. hominis declararon tener algún síntoma gastrointestinal. La asociación de B. hominis con dolor abdominal y beber agua de la llave tuvo diferencia significativa. Proponemos una transición parasitaria a B. hominis como principal parásito del hombre, como resultado de las medidas de control para las parasitosis intestinales.

Blastocystis hominis is an enteric emergen organism found in human it's prevalence has been increasing in the lasts years. The frequency in Mexico is from 4.0 percent to 62 percent, without reports in the Guerrero state. The aim of this study was to inform the parasitic transition to B. hominis in the Central Zone of Guerrero state. The population in this study were three communities of Guerrero state: Chilpancingo, Petaquilla and Tixtla in a total of 1,138 preschools and schools children of both sexs. Three parasitological tests were used for detection of the parasite in stool specimens: micrscopy of direct smears, concentration and flotation technique and serum-solution saline culture. Global prevalence of parasites was of 38 percent and B. hominis was the principal parasite with 61 percent on the positive tests. The 90 percent were only B. hominis and 10 percent with others parasites. A total of 58 percent of the children healthy with B. hominis declarated have gastrointestinal symptoms. The association ofB. hominis with abdominal pain and drinking taste water had significant difference. We propuse a parasitic transition to B. hominis as principal human parasite, this can be the result of man-made intervention in the intestinal parasitosis control.

Frequency of Blastocystis hominis and other intestinal parasites in stool samples examined at the Parasitology Laboratory of the School of Pharmaceutical Sciences at the São Paulo State University, Araraquara / Freqüência de Blastocystis hominis e outros enteroparasitas em amostras de fezes examinadas no Laboratório de Parasitologia da Faculdade de Ciências Farmacêuticas da Universidade Estadual Paulista, Araraquara

Blastocystis homins is a protozoan that causes an intestinal infection known as human blastocystosis. This infection is diagnosed by means of parasitological examination of stools and by permanent staining techniques. The present study was developed to evaluate the frequency of Blastocystis hominis infection among inhabitants of the Araraquara region, State of São Paulo, and to compare different methods for investigating this protozoan in feces samples. Evaluations on 503 stool samples were performed by means of direct fresh examination and using the techniques of Faust et al., Lutz and Rugai et al. In addition, the iron hematoxylin, trichrome and modified Kinyoun staining techniques were used. Out of the 503 samples examined, 174 (34.6 percent) were found to be positive for the presence of intestinal parasites. The most frequent protozoa and helminths were Entamoeba coli (14.6 percent) and Strongyloides stercoralis (6.7 percent), respectively. Blastocystis hominis was present in 23 (4.6 percent) fecal samples, with a predominately pasty consistency and without characterizing a condition of diarrhea. Despite the low frequency of Blastocystis hominis found in the Araraquara region, compared with other regions of Brazil, it is important to perform laboratory diagnostic tests for this protozoan. Its finding in fecal material is indicative of food and drinking water contamination. Since the transmission route for this parasite is accepted to be oral-fecal, this implies that the population needs guidance regarding hygiene and basic sanitation measures as a means for controlling health problems caused by enteroparasites.

Blastocystis hominis é um protozoário, causador de infecção intestinal denominada blastocistose humana, cujo diagnóstico é realizado pelo exame coproparasitológico e por meio de técnicas de coloração permanente. Este estudo foi desenvolvido para avaliar a freqüência da infecção por Blastocystis hominis em habitantes da região de Araraquara/SP, bem como comparar diferentes métodos para a pesquisa desse protozoário em amostras de fezes. Foram estudadas 503 amostras de fezes submetidas ao exame direto a fresco, às técnicas de Faust e cols, Lutz e de Rugai e cols, além das colorações pela hematoxilina férrica, tricrômio e de Kinyoun modificada. Entre as 503 amostras examinadas, 174 (34,6 por cento) apresentaram-se positivas para a presença de parasitas intestinais. O protozoário e o helminto mais freqüentes foram Entamoeba coli (14,6 por cento) e Strongyloides stercoralis (6,7 por cento), respectivamente. Blastocystis hominis foi observado em 23 (4,6 por cento) amostras fecais com consistência predominantemente pastosa, não caracterizando quadro diarréico. Apesar da baixa freqüência de Blastocystis hominis encontrada na região de Araraquara, comparativamente a outras regiões brasileiras, é importante a realização do diagnóstico laboratorial desse protozoário. O encontro de Blastocystis hominis em material fecal é indicativo de contaminação de alimentos e água de consumo, desde que se admita a rota de transmissão oral-fecal desse parasita, o que implica na orientação da população sobre as medidas de saneamento básico e higiene como meio para se controlar problemas de saúde ocasionados pelos enteroparasitas.

Intestinal protozoa and helminths among Terena Indians in the State of Mato Grosso do Sul: high prevalence of Blastocystis hominis

A parasitological survey was carried out among Terena Indians living in the Tereré settlement in the municipality of Sidrolândia, State of Mato Grosso do Sul, Brazil. Single samples of feces from 313 Indians were processed by means of the spontaneous sedimentation method. In the population studied, 73.5 percent were infected with at least one intestinal parasite or commensal. Protozoa predominated. Blastocystis hominis (40.9 percent), Entamoeba coli (33.2 percent) and Entamoeba histolytica/Entamoeba dispar (31.6 percent) were the most common. Bivariate analysis showed that females were generally more infected and presented higher rates of infection by Entamoeba histolytica/Entamoeba dispar and Entamoeba coli. Males were more infected by hookworms and Strongyloides stercoralis than females. The precarious sanitary conditions of the Tereré settlement are probably a contributory factor towards the high prevalence of intestinal protozoa.

Um inquérito parasitológico foi realizado em índios Terena da aldeia Tereré, do município de Sidrolândia, Estado do Mato Grosso do Sul, Brasil. Amostras únicas de fezes de 313 índios foram processadas pelo método de sedimentação espontânea. Na população estudada, 73.5 por cento estavam infectados por pelo menos um parasita ou comensal intestinal. Os protozoários predominaram. Blastocystis hominis (40.9 por cento), Entamoeba coli (33.2 por cento) e Entamoeba histolytica/Entamoeba dispar (31.6 por cento) foram os mais comuns. A análise bivariada demonstrou que as mulheres estavam mais infectadas no geral e apresentavam maior taxa de infecção para Entamoeba histolytica/Entamoeba dispar e Entamoeba coli. Os homens estavam mais infectados por ancilostomídeos e Strongyloides stercoralis que as mulheres. As precárias condições sanitárias da aldeia Tereré são provavelmente um fator contribuinte para a alta prevalência de protozoários.

Investigación de parásitos intestinales en una comunidad aborigen de la provincia de Salta / Survey of intestinal parasites among an aboriginal community in Salta

Se investigó la presencia de protozoarios y helmintos intestinales en una comunidad aborigen ubicada a 6 km de Tartagal, provincia de Salta, Argentina. La edad de los individuos estudiados estaba comprendida entre 1 y 49 años. Ciento doce muestras de materia fecal se recogieron en solución acética formolada (SAF). Cada muestra se recolectó en tres días, en forma alternada. Todas las muestras se procesaron por el método de concentración bifásico de Ritchie y la técnica de flotación de Faust. Para la investigación de Enterobius vermicularis, se recolectaron 68 muestras seriadas de 6 días en formol al 5% por escobillado anal. Para la búsqueda de Dientamoeba fragilis se utilizó la coloración tricrómica modificada de Gomori-Wheatley. Ciento seis individuos (94.6%) fueron positivos para parásitos entéricos. Cuarenta y cuatro sujetos (41.5%) estaban poliparasitados, con más de cuatro especies. Los parásitos más frecuentes entre los protozoarios fueron Blastocystis hominis (58.9%), Entamoeba coli (51.8%), Giardia lamblia (27.7%) y Entamoeba histolytica/E. dispar (24.1%). Entre los helmintos, los hallados con mayor frecuencia fueron uncinarias (58.0%), Hymenolepis nana (31.2%) y Strongyloides stercoralis (24.1%). Por primera vez se informa Entamoeba histolytica/E. dispar (24.1%) y Dientamoeba fragilis (2.7%) en una comunidad aborigen de los alrededores de Tartagal. Este estudio revela el problema de salud pública que constituyen las parasitosis intestinales en la comunidad indígena estudiada, en la que coexisten la falta de saneamiento y de abastecimiento de agua potable.

The prevalence of intestinal parasitoses by protozoans and helminths was determined in an aboriginal community located 6 km from Tartagal, province of Salta, Argentina. The age of the inhabitants studied ranged from 1 to 49 years old. A total of 112 stool samples were collected in sodium acetate-acetic acid- formalin solution (SAF). Each sample was obtained in three different days, alternatively. Ritchie biphasic concentration method and Faust flotation technique were applied. For survey of Enterobius vermicularis, 68 samples were collected during six consecutive days using anal swabs. For the diagnosis of Dientamoeba fragilis, the modified trichrome Gomori-Wheatley staining technique was used. One hundred and six (94.6%) subjects resulted positive for enteric parasites. Forty-four (41.5%) individuals were positive for four or more parasites. The parasites more frequently found were, among the protozoans Blastocystis hominis (58.9%), Entamoeba coli (51.8%), Giardia lamblia (27.7%) and Entamoeba histolytica/E. dispar (24.1%). Among the helminths, the most frequent were hookworms (58.0%), Hymenolepis nana (31.2%) and Strongyloides stercoralis (24.1%). This is the first time that Entamoeba histolytica/E. dispar (24.1%) and Dientamoeba fragilis (2.7%) have been registered in the suburbs of Tartagal. This study reveals how intestinal parasitoses constitute a critical problem of public health in aboriginal communities like the one examined, where the lack of adequate sanitation conditions and unsuitable supply of water coexist.

Observações sobre Blastocystis hominis e Cyclospora cayetanensis em exames parasitológicos efetuados rotineiramente / Observations on Blastocystis hominis and Cyclospora cayetanensis in routine parasitological examinations

Relatamos algumas observações, efetuadas com exames parasitológicos de fezes, em atividades rotineiras: os métodos de Faust e cols e de sedimentação espontânea em água não servem para evidenciação de Blastocystis hominis; foram encontradas expressivas porcentagens de presença desse protozoário, sobretudo quando realizada coloração pela hematoxilina férrica; houve 0,7 por cento de registro de positividade para Cyclospora cayetanensis, sugerindo inclusão habitual de pesquisa, por técnicas apropriadas, de tal parasita.

We report some observations made from routine parasitological examinations on feces. The methods of Faust et al. and of spontaneous sedimentation in water are not enough to identify Blastocystis hominis. Significant percentage presence of this protozoan was found, especially when staining with iron hematoxylin was performed. Cyclospora cayetanensis was found in 0.7 percent of the cases, which suggests that this parasite should also routinely be investigated by appropriate techniques.

Prevalence and clinical features of blastocystis hominis infection among patients in Sebha, Libya

To determine the prevalence and seasonal variation, and to assess the clinical manifestations and treatment of blastocystosis in Libyan patients. Three thousand six hundred and forty five stool samples were screened for Blastocystis hominis using normal saline and iodine solution preparations. The clinical features of 108 patients were described, in whom B. hominis was the only parasite isolated. Fifty symptomatic patients were treated with 1500 mg metronidazole daily for 7 days and their stools were re-investigated for B. hominis. B. hominis was found in 969 [26.58%] of 3645 stool specimens examined. The infection of B. hominis was significantly more [p < 0.05] in summer than in winter over a three year period. In a prospective study of 108 patients, the most common symptoms with stools positive only for B. hominis were diarrhoea [84.94%], abdominal pain [66.66%], flatulence [17.20%] and vomiting [16.12%]. High concentration of B. hominis cells were found more in symptomatic patients than asymptomatic ones [9.20 cells per 40 X field versus 4.06 respectively] with statistically significant differences [p < 0.001]. Patients with B. hominis responded to metronidazole and were fully cured after 7 days. The occurrence of B. hominis infections in outpatients are probably related to weather conditions, with the suggestion that the hot, dry weather of the Sebha region favors the development and transmission of this organism. B. hominis infections might have a role in some pathological conditions, resulting in gastrointestinal symptoms

Prevalence of Blastocystis hominis infection in asymptomatic individuals from Bangkok, Thailand.

Fresh stool examination was performed from 2,230 participants who enrolled in annual check-up programs of the Faculty of Medical Technology, Mahidol University in 1999-2000 and 2004. In this study, Blastocystis hominis infection was diagnosed by culturing in Jones' media. A total of 21% of fecal specimens (in 1999-2000) and 13.7% (in 2004) were positive for B. hominis. The vacuolated form was the predominant form found in culture solution after 48 hours of incubation. The distribution of infection was highest between the ages of 21-30 years (p<0.05). There was no significant difference in infection between male and female groups. Other parasites, eg Giardia lamblia, Entamoeba histolytica, Entamoeba coli, Endolimax nana, Trichomonas hominis, Strongyloides stercoralis, Opisthorchis viverrini and Taenia species, were also found by fresh stool examination.

Blastocystis hominis and other intestinal parasites in a community of Pitanga City, Paraná State, Brazil

O presente trabalho foi realizado no período de agosto a outubro de 2004 com o objetivo de se estimar a prevalência de Blastocystis hominis, avaliar a eficácia de diferentes técnicas para o seu diagnóstico assim como estimar a prevalência de outros parasitas intestinais na comunidade de Campo Verde, município de Pitanga. Amostras de fezes de crianças e adultos foram coletadas e submetidas às técnicas de exame direto, de flutuação em solução de sulfato de zinco, de sedimentação em tubo, de sedimentação em formol-éter e de coloração pelos métodos de Kinyoun e de hematoxilina férrica. Protozoários e/ou helmintos intestinais foram detectados em 128 (70,7%) das 181 amostras de fezes analisadas. As espécies mais prevalentes foram Endolimax nana (33,7%); B. hominis (26,5%); Giardia lamblia (18,2%); Entamoeba coli (17,1%); Ascaris lumbricoides (16,6%); Iodamoeba bütschlii (9,4%) e ancilostomídeos (7,7%). B. hominis foi identificado apenas pelas técnicas de exame direto, de sedimentação em formol-éter e de coloração pela hematoxilina férrica, sendo que esta última se mostrou menos sensível que às demais. A alta freqüência de B. hominis evidenciada por este estudo indica a necessidade de se incluir na rotina do laboratório técnicas que permitam a identificação deste parasita.

Elevada prevalência de blastocistose em pacientes do Centro de Saúde de Soledad, Estado Anzoátegui, Venezuela / Blastocystosis: a high prevalence of cases found in patients from Health Center of Soledad, Anzoategui State, Venezuela

Entre 98 exames parasitológicos de fezes de pacientes do Centro de Saúde de Soledad, Anzoátegui, Venezuela, foram encontrados 46 (46,9 por cento) positivos para Blastocystis hominis.

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.

Epidemiological survey of Giardia spp. and Blastocystis hominis in an Argentinian rural community

The aim of this study was to relate personal data, socio-cultural and environmental characteristics, and the presence of symptoms/signs with the frequencies of Giardia spp. and Blastocystis hominis among a rural population in Buenos Aires Province, Argentina. Of the surveyed population (350), 3.7% were infected with only Giardia spp. or 22.9% with B. hominis, and 2.3% were infected with both protozoa. The frequency of infection according to sex; 6.1% of males were infected and 1.6% of females by Giardia spp., 26.7% and 19.5% by B. hominis, and 2.4% and 2.2% by both parasites, respectively. Giardia spp. was detected in only three adults (over 14 years), but B. hominis was more frequent in adults than in children. The prevalences of these protozoa in this community are lower than those reported by other Argentinean studies, which is probably associated with the low density of the studied population (5.95 inhab/km2). Statistical analysis revealed that a male sex, flooding of the home, the use of a latrine, and an abdominal pain were correlated with the presence of these parasites, which indicate the importance of these factors in rural communities.

Blastocystis hominis--an emerging cause of diarrhoea in renal transplant recipients.

Blastocystis hominis is an intestinal protozoan that is emerging as an important cause of diarrhea in the immunosuppressed population. We report two cases of diarrhea caused by this organism in renal transplant recipients. The infection was diagnosed promptly by careful stool examination and treated successfully with metronidazole. These case report highlights the fact that unusual parasites like Blastocystis hominis should be looked for and treated in cases of diarrhea occurring in renal transplant recipients. This reduces the rate of post-transplant morbidity and mortality.

Transmission of intestinal blastocystosis related to the quality of drinking water.

A cross-sectional study was performed to evaluate the risk factors of Blastocystis hominis infection in the Thai army population of the 11th Infantry Division, Chachoengsao Province, Thailand. 201 army personnel and their family members were enrolled in this study. Intestinal parasitic infections in this population were assessed by stool examination using simple smear, formalin/ether technique and Kato-thick smear. Approximately one third of the specimens were positive for one or more intestinal parasites. With the prevalence of 21.9%, B. hominis was the most common intestinal parasite found in this population. Our data indicated that blastocystosis in this army population was significantly linked to the quality of drinking water. After being adjusted for potential confounders, consuming neither filtered nor boiled water was independently associated with blastocystosis.

Tinta china modificada para la detección de formas encapsuladas de Blastocystis hominis / Modified India ink for detection of capsulated forms of Blastocystis hominis

Se estudió la presencia de formas encapsuladas de Blastocystis hominis en 400 muestras fecales de pacientes pediátricos en los que se había detectado previamente este agente con salino y lugol. Se utilizó la técnica de tinta china modificada para visualizar la cápsula. De ese total, 120 muestras (30 por ciento) resultaron positivas. Se propone el uso de esta técnica para identificar las formas encapsuladas de B. hominis, puesto que la cápsula podría ser un factor de patogenicidad del agente

Enteroparasitos en niños residentes en zona rural del Partido del Carmen de Patagones: Provincia de Buenos Aires, Argentina / Enteroparasites in children living in rural areas at the Partido de Carmen de Patagones: province of Buenos Aires, Argentina

Como parte del programa de atención primaria de la salud (APS) del año 1996, y en virtud que no existían datos epidemiológicos referidos a enteroparásitos hallados en niños de 0 a 14 años, residentes en una zona rural del Partido de Carmen de Patagones, Provincia de Buenos Aires, es que se realizó el presente estudio epidemiológico descriptivo. Se estudiaron 210 niños a los que se les efectúo un estudio parasitoscópico seriado de materia fecal y mucus anal. Los resultados mostraron que el 60,5 por ciento de la población estudiada era portadora de algún parásito intestinal. El monoparasitismo hallado fue de 67 por ciento, mientras que 33 por ciento restante presentó entre 2 y 5 formas parasitarias. El espectro parasitario fue el siguiente: entamoeba coli 31,5 por ciento, giardia lamblia 24,7 por ciento; enterobius vermicularis 18 por ciento; hymenolepis nana 10,4 por ciento; blastocystis hominis 10,4 por ciento; 10,3 por ciento; chilomastix mesnili 2,5 por ciento; entamoeba hystolytica 0,9 por ciento y trichuris 0,5 por ciento. La distribución parasitaria en los distintos sectores estudiados fue en general homogénea excepto para H. nana la cual presentó una prevalencia más altas en zonas de riesgos con relación a la zona seca. Los resultados obtenidos fueron comunicados a las autoridades sanitarias correspondientes

Variación estacional de las infecciones por protozoos intestinales en pacientes ambulatorios del sector norte de Santiago, Chile: 1995-1996 / Seasonal variation of intestinal protozoa infections in outpatients of the north section of 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 percent in 1995-1996 respectively. Prevalence of giardia intestinalis infections decreased from 16.6-17.4 per cent in the 0-9 year-old children group to 4.1-4.5 percent 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 dry-warmy period (october-march) were the same. On the contrary, more cases of B. hominis infection 25.8 percent versus 18.2 percent (this difference being statistically significant, p >0.001) were observed during rainy-cold months of the year

Diagnosis of blastocystis hominis by different staining techniques

150 stool samples were collected from diarrheic patients of different ages and examined for Blastocystis hominis by direct smears and concentrated by Sheather's sugar flotation. Staining was done by Giemsa, 2 modifications of trichrome stain, modified Ziehl-Neelsen, Safranin-methylene blue and 2-auramine stains. Out of the 150 cases, 9 were positive for blastocystosis. The best stains were Safranin- methylene blue and modified Ziehl-Neelsen stains. They had the advantage of staining cysts and amoeboid forms besides being rapid and easy to perform. The modified trichrome stains were less specific and time-consuming. Giemsa stain was not an efficient stain. Scanning and transmission electron microscopy [SEM and TEM] were performed to study the fine ultrastructure

Enteroparasitosis en la población de la tercera edad consultante en centros médicos de la Pontificia Universidad Católica de Chile, 1997 / Enteroparasitic infections in aged outpatiens from medical centers of Pontificia Universidad Católica de Chile, 1997

La población senil rara vez ha sido estudiada específicamente para determinar prevalencia de enteroparasitosis y sus repercusiones. Por lo anterior, se realizó un estudio retrospectivo a partir de 493 exámenes coproparasitológicos seriados analizados por técnica de PAF y Téleman y 9 test de Graham realizados a pacientes senescentes en el laboratorio de parasitología de la Pontificia Universidad Católica de Chile, entre el 1º de enero al 31 de Diciembre de 1997. Los resultados fueron analizados por sexo, edad, especies, y estación del año. Al analizar los resultados se encontró presencia de parásitos y/o comensales un 37,7 por ciento de los exámenes, de los cuales un 38,7 por ciento corresponde a parásitos, un 26,3 por ciento a comensales y un 34,9 por ciento ambos 20,3 por ciento presentó una sola especie, siendo el agente más frecuente el protozoo blastocystis hominis 23,1 por ciento, seguido por los comensales endolimax nana y entamoeba coli con 14,1 por ciento y 12,7 por ciento respectivamente. Afecta en forma similar a ambos sexos y sin variación significativa estacional. A diferencia de los grupos pediátricos, giardia lamblia no constituyó un agente frecuente en la tercera edad. Finalmente se considera necesario fomentar la realización de nuevos estudios que permitan conocer y mejorar aún más el manejo de la patología del paciente senescente, dada la mayor esperanza de vida que existe para éstos actualmente en las puertas del siglo XXI