Prevalence of intestinal parasites and risk factors forspecific and multiple helminth infections in a remote city of the Brazilian Amazon.

INTRODUCTION: Few studies have described the risk factors of intestinal parasitic infections in the Amazon. METHODS: A cross-sectional survey was performed in a City of the State of Amazonas (Brazil) to estimate the prevalence of intestinal parasites and determine the risk factors for helminth infections. RESULTS: Ascaris lumbricoides was the most prevalent parasite. The main risk factors determined were: not having a latrine for A. lumbricoides infection; being male and having earth or wood floors for hookworm infection; and being male for multiple helminth infections. CONCLUSIONS: We reported a high prevalence of intestinal parasites and determined some poverty-related risk factors.

Genetic diversity of Cryptosporidium identified in clinical samples from cities in Brazil and Argentina.

The identification and characterisation of Cryptosporidium genotypes and subtypes are fundamental to the study of cryptosporidiosis epidemiology, aiding in prevention and control strategies. The objective was to determine the genetic diversity of Cryptosporidium in samples obtained from hospitals of Rio de Janeiro, Brazil, and Buenos Aires, Argentina. Samples were analysed by microscopy and TaqMan polymerase chain reaction (PCR) assays for Cryptosporidium detection, genotyped by nested-PCR-restriction fragment length polymorphism (RFLP) analysis of the 18S rRNA gene and subtyped by DNA sequencing of the gp60 gene. Among the 89 samples from Rio de Janeiro, Cryptosporidium spp were detected in 26 by microscopy/TaqMan PCR. In samples from Buenos Aires,Cryptosporidium was diagnosed in 15 patients of the 132 studied. The TaqMan PCR and the nested-PCR-RFLP detected Cryptosporidium parvum, Cryptosporidium hominis, and co-infections of both species. In Brazilian samples, the subtypes IbA10G2 and IIcA5G3 were observed. The subtypes found in Argentinean samples were IbA10G2, IaA10G1R4, IaA11G1R4, and IeA11G3T3, and mixed subtypes of Ia and IIa families were detected in the co-infections. C. hominis was the species more frequently detected, and subtype family Ib was reported in both countries. Subtype diversity was higher in Buenos Aires than in Rio de Janeiro and two new subtypes were described for the first time.

Genetic diversity of Cryptosporidium identified in clinical samples from cities in Brazil and Argentina

The identification and characterisation of Cryptosporidiumgenotypes and subtypes are fundamental to the study of cryptosporidiosis epidemiology, aiding in prevention and control strategies. The objective was to determine the genetic diversity ofCryptosporidium in samples obtained from hospitals of Rio de Janeiro, Brazil, and Buenos Aires, Argentina. Samples were analysed by microscopy and TaqMan polymerase chain reaction (PCR) assays forCryptosporidium detection, genotyped by nested-PCR-restriction fragment length polymorphism (RFLP) analysis of the 18S rRNA gene and subtyped by DNA sequencing of the gp60 gene. Among the 89 samples from Rio de Janeiro, Cryptosporidium spp were detected in 26 by microscopy/TaqMan PCR. In samples from Buenos Aires,Cryptosporidium was diagnosed in 15 patients of the 132 studied. The TaqMan PCR and the nested-PCR-RFLP detected Cryptosporidium parvum, Cryptosporidium hominis, and co-infections of both species. In Brazilian samples, the subtypes IbA10G2 and IIcA5G3 were observed. The subtypes found in Argentinean samples were IbA10G2, IaA10G1R4, IaA11G1R4, and IeA11G3T3, and mixed subtypes of Ia and IIa families were detected in the co-infections. C. hominis was the species more frequently detected, and subtype family Ib was reported in both countries. Subtype diversity was higher in Buenos Aires than in Rio de Janeiro and two new subtypes were described for the first time.

Blastocystis sp. in splenic cysts: causative agent or accidental association? A unique case report.

BACKGROUND: Blastocystis sp. is one of the most prevalent parasites found in human stool and has been recently considered an opportunistic emerging pathogen in immunocompromised individuals. However, cases of invasive intestinal infections and skin rashes have been attributed to infection by Blastocystis sp in immunocompetent individuals, suggesting that it is an emerging parasite with pathogenic potential. FINDINGS: We present a case of a 22 year old female patient who complained of pain in the left hypochondrium. Ultrasonography and abdominal computed tomography scans showed two splenic cysts. The cyst fluid analysis demonstrated numerous Blastocystis sp.; PCR and DNA sequencing analyses confirmed the presence of Blastocystis subtype 3. CONCLUSIONS: This is, to our knowledge, the first case report of the presence of Blastocystis subtype 3 in extra-intestinal organs and is strong evidence that Blastocystis sp. is potentially pathogenic and invasive. However, further studies are required to determine the pathogenicity of the parasite.

First case report of infection caused by Encephalitozoon intestinalis in a domestic cat and a patient with AIDS.

Microsporidia are eukaryotic, intracellular obligate parasites that infect invertebrate and vertebrate animals, and have emerged as important opportunistic parasites in AIDS patients. We used light microscopy to detect microsporidial spores in stool samples of a domestic cat confirmed as Encephalitozoon intestinalis by PCR, owned by an AIDS patient with chronic diarrhea and E. intestinalis infection. Cats can be considered hosts of E. intestinalis.

Tuberculose e parasitismo intestinal em população indígena na Amazônia brasileira / Tuberculosis y parasitismo intestinal en población indígena en el Amazonas Brasilero / Tuberculosis and intestinal parasitism among indigenous people in the Brazilian Amazon region

O objetivo do estudo foi estimar as freqüências de tuberculose e parasitoses intestinais na em comunidades indígenas da localidade de Iauareté (AM), em 2001. Estudo transversal (n=333) visando à obtenção de dados demográficos e amostras biológicas para exames de escarro e fezes. Dentre os 43 sintomáticos respiratórios, seis foram positivos na pesquisa de bacilos álcool-ácido resistentes no escarro. As parasitoses intestinais apresentaram freqüência significativamente maior entre a população Hüpda do que entre os índios que habitam os demais bairros (37,5 por cento vs. 19,3 por cento para Ascaris lumbricoides, 32,4 por cento vs. 16,3 por cento para Trichuris trichiura, 75 por cento vs. 19,3 por cento para ancilostomídeos, 75 por cento vs. 35,4 por cento para Entamoeba histolyticaD dispar e 33,3 por cento vs. 10,7 por cento para Giardia lamblia). Conclui-se que a tuberculose e o parasitismo intestinal são freqüentes nessas comunidades, exigindo medidas de controle e melhorias na assistência à saúde.

The objective of the survey was to estimate the frequencies of tuberculosis and intestinal parasitosis in indigenous communities at the locality of Iauareté, Northern Brazil, in 2001. This was a cross-sectional survey (n=333) aimed at obtaining demographic data and biological samples for sputum and feces examinations. Among the 43 individuals with respiratory symptoms, six presented alcohol/acid-fast bacilli in sputum. Intestinal parasitosis was significantly more frequent among the Hüpda population than among the Indians living in other districts (37.5 percent vs. 19.3 percent for Ascaris lumbricoides, 32.4 percent vs. 16.3 percent for Trichuris trichiura, 75 percent vs. 19.3 percent for hookworms, 75 percent vs. 35.4 percent for Entamoeba histolyticaD dispar and 33.3 percent vs. 10.7 percent for Giardia lamblia). It is concluded that tuberculosis and intestinal parasitism are frequent in these communities, thus requiring control measures and better medical care.

El objetivo del estudio fue estimar las frecuencias de tuberculosis y parasitosis intestinales en las comunidades indígenas de la localidad de Iauareté (Norte de Brasil), en 2001. Estudio transversal (n=333) intentando obtener datos demográficos y muestras biológicas para examenes de esputo y heces. Entre los 43 sintomáticos respiratorios, seis fueron positivos en la pesquisa de bacilos alcohol-ácido resistentes en el esputo. Las parasitosis intestinales presentaron frecuencia significativamente mayor entre la población Hüpda que entre los indios que habitan las demás localidades (37,5 por ciento vs. 19,3 por ciento para Ascaris lumbricoides, 32,4 por ciento vs. 16,3 por ciento para Trichuris trichiura, 75 por ciento vs. 19,3 por ciento para ancilostomídeos, 75 por ciento vs. 35,4 por ciento para Entamoeba histolytica/dispar y 33,3 por ciento vs. 10,7 por ciento para Giardia lamblia). Se concluyó que la tuberculosis y el parasitismo intestinal son frecuentes en esas comunidades, exigiendo medidas de control y mejorías en la asistencia a la salud.

Tuberculosis and intestinal parasitism among indigenous people in the Brazilian Amazon region.

The objective of the survey was to estimate the frequencies of tuberculosis and intestinal parasitosis in indigenous communities at the locality of Iauareté, Northern Brazil, in 2001. This was a cross-sectional survey (n=333) aimed at obtaining demographic data and biological samples for sputum and feces examinations. Among the 43 individuals with respiratory symptoms, six presented alcohol/acid-fast bacilli in sputum. Intestinal parasitosis was significantly more frequent among the Hüpda population than among the Indians living in other districts (37.5% vs. 19.3% for Ascaris lumbricoides, 32.4% vs. 16.3% for Trichuris trichiura, 75% vs. 19.3% for hookworms, 75% vs. 35.4% for Entamoeba histolyticaD dispar and 33.3% vs. 10.7% for Giardia lamblia). It is concluded that tuberculosis and intestinal parasitism are frequent in these communities, thus requiring control measures and better medical care.

Seroprevalence of Toxoplasma gondii infection among indian people living in Iauareté, São Gabriel da Cachoeira, Amazonas, Brazil.

The goal of this survey was to estimate the seroprevalence of Toxoplasma gondii infection in Iauareté, a multiethnic Indian community in the upper Rio Negro basin. We carried out a cross-sectional survey (n = 260), in order to obtain serum samples and demographic data. The sample was randomly selected, by family conglomerate analysis. Serodiagnosis was performed by an enzyme-linked immunosorbent assay and indirect immunofluorescence. Prevalence of reactivity was 73.5% (191/260), being higher in the older-age groups, reaching 95.7% (44/46) in the group aged 50 years or more. The majority of seropositive subjects had titers equal to or less than 1:64. Seroprevalence was greater in Indians belonging to the Hupda ethnic group (p = 0.03). According to the present survey, Indian people living in Iauareté have a high prevalence of antibodies to T. gondii. Demographic concentration and urbanization within low sanitation and poor hygiene backgrounds, as well as unfiltered water consumption, may be related to the high frequency of T. gondii seroprevalence observed in the studied area.

Seroprevalence of Toxoplasma gondii infection among indian people living in Iauareté, São Gabriel da Cachoeira, Amazonas, Brazil / Soroprevalência da infecção por Toxoplasma gondii em populações indígenas de Iauareté, São Gabriel da Cachoeira, Amazonas, Brasil

The goal of this survey was to estimate the seroprevalence of Toxoplasma gondii infection in Iauareté, a multiethnic Indian community in the upper Rio Negro basin. We carried out a cross-sectional survey (n = 260), in order to obtain serum samples and demographic data. The sample was randomly selected, by family conglomerate analysis. Serodiagnosis was performed by an enzyme-linked immunosorbent assay and indirect immunofluorescence. Prevalence of reactivity was 73.5 percent (191/260), being higher in the older-age groups, reaching 95.7 percent (44/46) in the group aged 50 years or more. The majority of seropositive subjects had titers equal to or less than 1:64. Seroprevalence was greater in Indians belonging to the Hupda ethnic group (p = 0.03). According to the present survey, Indian people living in Iauareté have a high prevalence of antibodies to T. gondii. Demographic concentration and urbanization within low sanitation and poor hygiene backgrounds, as well as unfiltered water consumption, may be related to the high frequency of T. gondii seroprevalence observed in the studied area.

Este estudo objetivou estimar a soroprevalência da infecção por Toxoplasma gondii em Iauareté, uma comunidade indígena multiétnica situada na bacia do Alto Rio Negro. Foi realizado um estudo seccional (n = 260), obtendo-se amostras de soro e dados demográficos, através de amostragem sistemática por conglomerado. Os testes sorológicos foram realizados através de ensaio imunoenzimático e imunofluorescência indireta. A prevalência da reatividade foi de 73,5 por cento (191/260), aumentando com a faixa etária e atingindo 95,7 por cento (44/46) em maiores de 50 anos. A maioria das amostras reativas apresentou títulos iguais ou inferiores a 1:64. Observou-se maior freqüência de reatividade entre os índios da etnia Maku Hupda. De acordo com o presente estudo, a população indígena de Iauareté apresenta alta prevalência da presença de anticorpos contra T. gondii. A concentração demográfica e a urbanização, conduzidas sem infra-estrutura sanitária, levadas a cabo na região no ultimo século, podem estar relacionadas à alta freqüência de detecção de anticorpos contra T. gondii na área estudada.

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.

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% were infected with at least one intestinal parasite or commensal. Protozoa predominated. Blastocystis hominis (40.9%), Entamoeba coli (33.2%) and Entamoeba histolytica/Entamoeba dispar (31.6%) 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.

Mass treatment for intestinal helminthiasis control in an Amazonian endemic area in Brazil.

The objective of the present study was to estimate the prevalence of soil-transmitted helminthiasis and evaluate the sanitary conditions and the role of a mass treatment campaign for control of these infections in Santa Isabel do Rio Negro. A cross-sectional survey was carried out in 2002, to obtain data related to the sanitary conditions of the population and fecal samples for parasitological examination in 308 individuals, followed by a mass treatment with albendazole or mebendazole with coverage of 83% of the city population in 2003. A new survey was carried out in 2004, involving 214 individuals, for comparison of the prevalences of intestinal parasitosis before and after the mass treatment. The prevalences of ascariasis, trichuriasis and hookworm infection were 48%; 27% and 21% respectively in 2002. There was a significant decrease for the frequency of infections by Ascaris lumbricoides (p < 0.05; OR / 95% CI = 0.44 / 0.30 - 0.65), Trichuris trichiura (p < 0.05; OR / 95% CI = 0.37 / 0.22 - 0.62), hookworm (p < 0.05; OR / 95% CI = 0.03 / 0.01 - 0.15) and helminth poliparasitism (p < 0.05; OR / 95% CI = 0.16 / 0.08 - 0.32). It was also noticed a decrease of prevalence of infection by Entamoeba histolytica / dispar (p < 0.05; OR / 95% CI = 0.30 / 0.19 - 0.49) and non-pathogenic amoebas. It was inferred that a mass treatment can contribute to the control of soil-transmitted helminthiasis as a practicable short-dated measure. However, governmental plans for public health, education and urban infrastructure are essential for the sustained reduction of prevalences of those infections.

Mass treatment for intestinal helminthisis control in an Amazonian endemic area in Brazil / Tratamento em massa para controle das helmintíases intestinais em área endêmica na Amazônia Brasileira

The objective of the present study was to estimate the prevalence of soil-transmitted helminthiasis and evaluate the sanitary conditions and the role of a mass treatment campaign for control of these infections in Santa Isabel do Rio Negro. A cross-sectional survey was carried out in 2002, to obtain data related to the sanitary conditions of the population and fecal samples for parasitological examination in 308 individuals, followed by a mass treatment with albendazole or mebendazole with coverage of 83 percent of the city population in 2003. A new survey was carried out in 2004, involving 214 individuals, for comparison of the prevalences of intestinal parasitosis before and after the mass treatment. The prevalences of ascariasis, trichuriasis and hookworm infection were 48 percent; 27 percent and 21 percent respectively in 2002. There was a significant decrease for the frequency of infections by Ascaris lumbricoides (p < 0.05; OR / 95 percent CI = 0.44 / 0.30 - 0.65), Trichuris trichiura (p < 0.05; OR / 95 percent CI = 0.37 / 0.22 - 0.62), hookworm (p < 0.05; OR / 95 percent CI = 0.03 / 0.01 - 0.15) and helminth poliparasitism (p < 0.05; OR / 95 percent CI = 0.16 / 0.08 - 0.32). It was also noticed a decrease of prevalence of infection by Entamoeba histolytica / dispar (p < 0.05; OR / 95 percent CI = 0.30 / 0.19 - 0.49) and non-pathogenic amoebas. It was inferred that a mass treatment can contribute to the control of soil-transmitted helminthiasis as a practicable short-dated measure. However, governmental plans for public health, education and urban infrastructure are essential for the sustained reduction of prevalences of those infections.

O presente trabalho objetivou avaliar a prevalência e o papel de um tratamento em massa das helmintíases intestinais em Santa Isabel do Rio Negro, Estado do Amazonas, Brasil. Foi realizado em 2002 um estudo seccional, incluindo inquérito copro-parasitológico, objetivando a obtenção das prevalências das parasitoses intestinais e dados sobre as condições sanitárias do local, estudando-se uma amostra de 308 indivíduos. Em 2003 foi realizada intervenção para tratamento em massa das helmintíases intestinais com administração de albendazol (ou mebendazol para crianças entre 12 e 24 meses) na sede do município, alcançando-se 83 por cento de cobertura. Novo inquérito copro-parasitológico foi realizado em 2004, para comparação das prevalências antes a após o tratamento. As prevalências das infecções por Ascaris lumbricoides, Trichuris trichiura e ancilostomídeos foram 48 por cento, 27 por cento e 21 por cento, respectivamente em 2002. Em 2004 observou-se redução significativa das infecções por Ascaris lumbricoides (p < 0,05; OR / 95 por cento IC = 0,44 / 0,30 - 0,65), Trichuris trichiura (p < 0,05; OR / 95 por cento IC = 0,37 / 0,22 - 0,62), ancilostomídeos (p < 0,05; OR / 95 por cento IC = 0,03 / 0,01 - 0,15) e poliparasitismo por helmintos intestinais (p < 0,05; OR / 95 por cento IC = 0,16 / 0,08 - 0,32). Foi também observada redução da prevalência de infecção por Entamoeba histolytica/dispar (p < 0,05; OR / 95 por cento CI = 0,30 / 0,19 - 0,49). Concluiu-se que o tratamento em massa pode auxiliar o controle das helmintíases intestinais, porém ações governamentais em infraestrutura urbana e educação são essenciais para uma redução sustentada das prevalências destas infecções.

Novos aspectos sobre um tema bem conhecido: cryptosporidium / News aspects about a well known theme: cryptosporidium

Cryptosporidium é um protozoário parasita cuja importância emergiu paralelamente aos primeiros casos de HIV/SIDA. O curso clínico da infecçäo está diretamente relacionado ao estado imunológico do indivíduo. A criptosporidiose é uma zoonose, sendo a infecçäo registrada em cerca de 152 diferentes hospedeiros mamíferos. A protozoose atinge os indivíduos imunocompetentes como crianças que freqüentam creches. Nos últimos anos, estudos empregando técnicas moleculares revolucionaram o conhecimento sobre o protozoário. Nessa revisäo, importantes e novos aspectos da criptosporidiose e seu agente etiológico säo discutidos, como a validade das distintas espécies, os diferentes genótipos e a relevância do seu diagnóstico à luz da Parasitologia Clínica no Brasil

Clinical and diagnostic aspects of intestinal microsporidiosis in HIV-infected patients with chronic diarrhea in Rio de Janeiro, Brazil

The objectives of this study were to determine both the prevalence of microsporidial intestinal infection and the clinical outcome of the disease in a cohort of 40 HIV-infected patients presenting with chronic diarrhea in Rio de Janeiro, Brazil. Each patient, after clinical evaluation, had stools and intestinal fragments examined for viral, bacterial and parasitic pathogens. Microsporidia were found in 11 patients (27.5 percent) either in stools or in duodenal or ileal biopsies. Microsporidial spores were found more frequently in stools than in biopsy fragments. Samples examined using transmission electron microscopy (n=3) or polymerase chain reaction (n=6) confirmed Enterocytozoon bieneusi as the causative agent. Microsporidia were the only potential enteric pathogens found in 5 of the 11 patients. Other pathogens were also detected in the intestinal tract of 21 patients, but diarrhea remained unexplained in 8. We concluded that microsporidial infection is frequently found in HIV infected persons in Rio de Janeiro, and it seems to be a marker of advanced stage of AIDS

Microsporidioses humanas: desenvolvimento de métodos para o diagnóstico morfológico das microsporidioses intestinais em pacientes HIV-Positivos no município do Rio de Janeiro

As infecções intestinais por Enterocytozoon bieneuse e Septata intestinalis têm sido frequêntemente diagnosticadas em pacientes com SIDA/AIDS. Entretanto a detecção de esporos de microsporídios nas fezes é particularmente difícil quando o número dessas estruturas de resistência é pequeno. A partir de um método específico para a detecção de oocistos de Cryptosporidium, desenvolveu-se neste trabalho uma modificação que permitiu a concentração de esporos de microsporídios nas fezes. Foram estudados 140 pacientes do Hospital Evandro Chagas/FIOCRUZ e 95 do Hospital Universitário Pedro Ernesto/UERJ, todos soropositivos para o vírus da imunodeficiência humana(HIV). As amostras fecais desses pacientes foram investigadas pelo método direto e pelo método de concentração, desenvolvido neste trabalho. Todas as lâminas foram coradas pelas técnicas do Chromotrope e do Gram-Chromotrope, sendo essa última coloração desenvolvida e testada durante os trabalhos experimentais. Foram obtidas prevalências++. para microsporídios de 17,86 por cento (método direto) e 25 por cento (método de concentração) no grupo de indivíduos do HEC/FIOCRUZ e de 11,58 por cento no grupo investigado do HUPE/UERJ. A microscopia eletrônica de transmissão, realizada em fragmentos de biópsia duodenal de um paciente com diagnóstico positivo pela microscopia óptica, permitiu a identificação de esporos que apresentaram ultra-estrutura caracter161stica, compatível com a espécie E. bieneusi. O número de pacientes que foi diagnosticado com microsporidiose intestinal no presente estudo mostrou que os microsporídios são importantes agentes de infecção em indivíduos portadores do vírus HIV no Município do Rio de Janeiro

Microsporidioses humanas: desenvolvimento de métodos para o diagnóstico morfológico das microsporidioses intestinais em pacientes HIV-Positivos no município do Rio de Janeiro / Microsporídiosis human: development of methods for the morphological diagnosis of intestinal microsporídiosis in HIV-positives in the municipality of Rio de Janeiro

As infecções intestinais por Enterocytozoon bieneuse e Septata intestinalis têm sido frequêntemente diagnosticadas em pacientes com SIDA/AIDS. Entretanto a detecção de esporos de microsporídios nas fezes é particularmente difícil quando o número dessas estruturas de resistência é pequeno. A partir de um método específico para a detecção de oocistos de Cryptosporidium, desenvolveu-se neste trabalho uma modificação que permitiu a concentração de esporos de microsporídios nas fezes. Foram estudados 140 pacientes do Hospital Evandro Chagas/FIOCRUZ e 95 do Hospital Universitário Pedro Ernesto/UERJ, todos soropositivos para o vírus da imunodeficiência humana(HIV). As amostras fecais desses pacientes foram investigadas pelo método direto e pelo método de concentração, desenvolvido neste trabalho. Todas as lâminas foram coradas pelas técnicas do Chromotrope e do Gram-Chromotrope, sendo essa última coloração desenvolvida e testada durante os trabalhos experimentais. Foram obtidas prevalências++. para microsporídios de 17,86 por cento (método direto) e 25 por cento (método de concentração) no grupo de indivíduos do HEC/FIOCRUZ e de 11,58 por cento no grupo investigado do HUPE/UERJ. A microscopia eletrônica de transmissão, realizada em fragmentos de biópsia duodenal de um paciente com diagnóstico positivo pela microscopia óptica, permitiu a identificação de esporos que apresentaram ultra-estrutura caracter161stica, compatível com a espécie E. bieneusi. O número de pacientes que foi diagnosticado com microsporidiose intestinal no presente estudo mostrou que os microsporídios são importantes agentes de infecção em indivíduos portadores do vírus HIV no Município do Rio de Janeiro