[An evaluation of the efficacy of the CSF method for diagnosing intestinal helminthiases]. / Uma avaliação sobre a eficácia do método CSF no diagnóstico de helmintíases intestinais.

The recently proposed CSF method for diagnosing intestinal helminthiases was compared with the other methods (direct; Faust et al.; spontaneous sedimentation in water; and Kato-Katz) that are routinely for this purpose. The CSF method performed satisfactorily, thus showing that this technique can be adopted for use in diagnoses or epidemiological analyses.

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

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% of the cases, which suggests that this parasite should also routinely be investigated by appropriate techniques.

Survival of Trypanosoma cruzi in sugar cane used to prepare juice.

Chagas disease can be transmitted to man by many different means, including contact with infected triatomine feces, blood transfusion, laboratory accidents, organ transplants, and congenital or oral routes. The latter mode has received considerable attention recently. In this assay, we evaluate the survival of Trypanosoma cruzi contaminating sugar cane used to prepare juice, as well as the viability and capacity for infection by the parasite after recovery. Thirty triatomines were contaminated with T. cruzi Y strain and 45 days later pieces of sugar cane were contaminated with the intestinal contents of the insects. The pieces were ground at different intervals after contamination (time=0, 1, 4, 6, 12 and 24 hours) and the juice extracted and analyzed. Different methods were used to show T. cruzi in the juice: direct analysis, hematocrit tube centrifugation and QBC, and experimental inoculation in 47 female BALB/c mice (five control mice and seven mice for each interval examined (five inoculated orally and two intraperitoneally). Positive results were found using the direct analysis and QBC methods for juice prepared up to 12 hours after initial contamination. However, by the centrifugation technique, positivity was found only up to four hours after contamination of the sugar cane. Inoculated animals showed parasitemia during a 14 day observation period, demonstrating the high survival rate of T. cruzi in sugar cane.

Could kDNA-PCR in Peripheral Blood Replace the Examination of Bone Marrow for the Diagnosis of Visceral Leishmaniasis?

The aim of this study was to evaluate whether the molecular (kDNA-PCR) and parasitological diagnosis in peripheral blood (PB) could replace the invasive and painful bone marrow collection (BM) in the diagnosis of visceral leishmaniasis (VL). PB from suspected VL patients was evaluated by parasitological and molecular techniques using as the gold standard (GS) a combination of clinical, epidemiological, and immunochromatographic test (PB-rK39) results and parasitological examination of BM. Based on the GS, 38 samples from 32 patients were grouped: Group 1, 20 samples of VL cases, and Group 2, 18 samples of non-VL cases. In order to evaluate the parasitological and molecular techniques in PB, the samples were examined. From Group 1, PB kDNA-PCR was positive in 20 samples and in 19 of 20 in BM kDNA-PCR examination. However, the parasitological examination of buffy coat was insensitive, being able to detect only 4 cases from Group 1. All samples from Group 2 were negative. We concluded that, for the diagnosis of visceral leishmaniasis, the parasitological examination of peripheral blood was not useful; however, molecular diagnosis by kDNA-PCR, performed in peripheral blood, could be useful to replace the parasitological examination of bone marrow.

Microwave treatment of human milk to prevent transmission of Chagas disease.

It is recognized that breast feeding is an alternative means of transmission of Chagas disease. However, thermal treatment of milk can prevent this occurrence. As domestic microwave ovens are becoming commonplace, the efficacy of microwave thermal treatment in inactivating Trypanosoma cruzi trypomastigotes in human milk was tested. Human milk samples infected with T. cruzi trypomastigotes (Y strain) from laboratory-infected mice, were heated to 63 degrees C in a domestic microwave oven (2,450 MHz, 700 W). Microscopical and serological examinations demonstrated that none of the animals inoculated orally or intraperitoneally with infected milk which had been treated, got the infection, while those inoculated with untreated, infected milk, became infected. It was concluded that the simple treatment prescribed, which can easily be done at home, was effective in inactivating T. cruzi trypomastigotes contained in human milk.

[Blastocystosis: controversy and indefinedness]. / Blastocistose: controvérsias e indefinições.

Blastocystosis is the infection caused by Blastocystis hominis. It is associated with frequent and unquestionably very important controversy and lack of definition, above all due to its implications for general assistance and medical care. In that connection, there is considerable disagreement on the subject of the pathogenicity of this protozoan, which should be categorically defined. Other aspects besides the above, require clarification through results from well conducted studies aiming at attributing Blastocystis hominis a proper role within the context of public health. Another matter worthy of attention is the diagnostic value of the parasitological stool examination, with the proviso that it is adequate, as are fecal smears suspended in saline solution or permanent mounts stained with iron hematoxylin or thionine. The use of inadequate techniques tends to produce false negative results, thereby impeding investigation into the real importance of this microorganism.

[Blastocystosis: a high proportion of cases found in schoolchildren of São Paulo, State of São Paulo, Brazil]. / Elevada porcentagem de blastocistose em escolares de São Paulo, SP.

As a part of medical assistance activities, parasitological examination of fecal samples from 227 school children from a public institution of São Paulo (SP) revealed a rather high proportion of results positive for Blastocystis hominis. Other protozoan and worm species were markedly scarcer, a peculiar situation according to our judgement. It is acknowledged that blastocystosis is still largely an indefinite and controversial subject, which deserves adequate analysis to avoid drawbacks in the sphere of action of public health and general medical assistance.

[Evaluation of the efficacy of azithromycin and pyrimethamine, for treatment of experimental infection of mice with Toxoplasma gondii cystogenic strain]. / Avaliação da eficácia da azitromicina e pirimetamina em camundongos infectados por cepa cistogênica de Toxoplasma gondii.

The efficacy of prolonged administration of azithromycin and pyrimethamine was evaluated in mice experimentally infected with cystogenic strain of Toxoplasma gondii. The animals were intraperitoneally inoculated with one cyst of T. gondii and after 20 days were allocated into four groups: GI, infected without treatment; GII, infected and treated with the association of pyrimethamine (12.5 mg/kg/day) and azithromycin (100 mg/kg/day); GIII, infected and treated with the same dose of pyrimethamine; and GIV, infected and treated in the same way with azithromycin. The oral treatment lasted 120 days, after this period all the animals were sacrificed and the count of cysts in the brain was done. The association of both drugs provided the best results, by diminishing the cyst count in the brain of the animals treated in this way.

A patient with erythema nodosus leprosum and Chagas cardiopathy: challenges in patient management and review of the literature.

We report a patient with severe multi-bacillary leprosy complicated by recurrent episodes of erythema nodosum necrotisans that required thalidomide and/or corticosteroids during follow-up. Although the patient was from an area to which Chagas disease is endemic, this diagnosis was initially missed and was only investigated when heart failure developed in the patient. The difficulties of managing erythema nodosum necrotisans and heart failure concomitantly and those involved in excluding the diagnosis of acute myocarditis caused by reactivation of Chagas disease secondary to the immunosuppressive regimen are discussed. Other potential causes for the heart failure and possible interactions between the two diseases and their treatments are discussed. We also reviewed the literature for the association between leprosy and Chagas disease, both of which are highly endemic in Brazil. This case emphasizes the importance of searching for subclinical co-infections in leprosy patients because reactions frequently develop during specific treatment in these patients, and these reactions require prolonged therapy with immunosuppressive drugs.

Could kDNA-PCR in peripheral blood replace the examination of bone marrow for the diagnosis of visceral leishmaniasis?

The aim of this study was to evaluate whether the molecular (kDNA-PCR) and parasitological diagnosis in peripheral blood (PB) could replace the invasive and painful bone marrow collection (BM) in the diagnosis of visceral leishmaniasis (VL). PB from suspected VL patients was evaluated by parasitological and molecular techniques using as the gold standard (GS) a combination of clinical, epidemiological, and immunochromatographic test (PB-rK39) results and parasitological examination of BM. Based on the GS, 38 samples from 32 patients were grouped: Group 1, 20 samples of VL cases, and Group 2, 18 samples of non-VL cases. In order to evaluate the parasitological and molecular techniques in PB, the samples were examined. From Group 1, PB kDNA-PCR was positive in 20 samples and in 19 of 20 in BM kDNA-PCR examination. However, the parasitological examination of buffy coat was insensitive, being able to detect only 4 cases from Group 1. All samples from Group 2 were negative. We concluded that, for the diagnosis of visceral leishmaniasis, the parasitological examination of peripheral blood was not useful; however, molecular diagnosis by kDNA-PCR, performed in peripheral blood, could be useful to replace the parasitological examination of bone marrow

[Intestinal parasitosis in Indians of the Mapuera community (Oriximiná, State of Pará, Brazil): high prevalence of Blastocystis hominis and finding of Cryptosporidium sp and Cyclospora cayetanensis]. / Parasitoses intestinais de indígenas da comunidade Mapuera (Oriximiná, Estado do Pará, Brasil): elevada prevalência de Blastocystis hominis e encontro de Cryptosporidium sp e Cyclospora cayetanensis.

Occurrences of intestinal parasitosis in Indians of the Mapuera community (Oriximiná, State of Pará, Brazil) were evaluated. Within the context of group assessment, this study makes a contribution towards adequate knowledge of this subject, which is significant from a medical-sanitary point of view. Parasitological examination of feces from 83 individuals, performed using four different methods, could be considered to have reasonable amplitude for establishing diagnoses. Protozoan cysts and helminth eggs of many types were found, even with significant percentages. The frequent presence of Blastocystis hominis (57.8%), along with findings of Cryptosporidium sp (3.6%) and Cyclospora cayetanensis (10.8%), deserved highlighting with specific comments. The findings show that these Indians live in an environment in which poor hygiene conditions prevail. In particular, these facilitate the dissemination of protozoa and helminths through contact with the soil or through intake of contaminated water and food.

False-positive results of a rapid K39-based strip test and Chagas disease.

BACKGROUND: The definitive diagnosis of visceral leishmaniasis (VL) requires invasive procedures with demonstration of amastigotes in tissue or promastigotes in culture. Unfortunately, these approaches require laboratory materials not available in poor countries where the disease is endemic. The correct diagnosis of VL is important, and made more difficult by the fact that several common tropical diseases such as malaria, disseminated tuberculosis, and enteric fever share the same clinical presentation. Serological tests have been developed to replace parasitological diagnosis in the field. A commercially available K39-based strip test for VL has been developed for this purpose. The endemic area of leishmaniasis in Brazil overlaps the endemic area of Chagas disease, a disease that can cause false-positive serological test results. The aim of this study was to evaluate the incidence of false-positive exams using a rapid test for VL in patients with Chagas disease. METHODS: A rapid test based on the recombinant K39 antigen of Leishmania was used in: (1) 30 patients with confirmed Chagas disease, (2) 30 patients with a serological diagnosis of Chagas disease by ELISA, indirect immunofluorescence, indirect hemagglutination, and chemiluminescence, (3) 30 healthy patients from a non-endemic area as the control group, (4) 30 patients with confirmed VL, and (5) 20 patients with proved cutaneous leishmaniasis. RESULTS: The sensitivity and specificity of the rapid strip test were 100% when compared with healthy volunteers and those with confirmed Chagas disease. One false-positive result occurred in the group with Chagas disease diagnosed by serological tests (specificity of 96%). CONCLUSION: The rapid test based on recombinant K39 is a useful diagnostic assay, and a false-positive result rarely occurs in patients with a serological diagnosis of Chagas disease.

Análise de técnicas parasitológicas utilizadas no seguimento de pacientes com doença de chagas e tratados por meio do transplante cardíaco / Analysis of parasitological techniques in the monitoring of patients with Chagas disease and treated by heart transplantation

Este estudo teve como objetivo analisar a função da hemocultura, do xenodiagnóstico e do creme leucocitário no acompanhamento e diagnóstico de possível reativação em pacientescrônicos tratados por meio do transplante de coração. Foram examinadas 70 amostras das quais15,7por cento (11/70) se mostraram positivas, sendo 8,5por cento (6/70) na hemocultura e 12,8por cento (9/70) noxenodiagnóstico. Apresentaram concordância nos dois métodos quatro amostras (36,36por cento). Nãohouve positividade no creme leucocitário. Os achados corroboram informações sobre a superiorsensibilidade do xenodiagnóstico em relação à hemocultura. A amostra do paciente 20, positiva noxenodiagnóstico (décimo quinto dia) e que apresentou miocardite com ninhos de amastigotas 15 dias antes dadetecção laboratorial, sinaliza a importância da leitura precoce dos exames parasitológicos comopreditivos de possível reativação da doença.

Parasitoses intestinais de indígenas da comunidade Mapuera (Oriximiná, Estado do Pará, Brasil): elevada prevalência de Blastocystis hominis e encontro de Cryptosporidium sp e Cyclospora cayetanensis / Intestinal parasitosis in Indians of the Mapuera community (Oriximiná, State of Pará, Brazil): high prevalence of Blastocystis hominis and finding of Cryptosporidium sp and Cyclospora cayetanensis

Foi avaliada a ocorrência de parasitoses intestinais em indígenas da aldeia Mapuera (Oriximiná, Estado do Pará, Brasil). No contexto de apreciações congêneres, expressa contribuição para adequado conhecimento do assunto, significativo sob o ponto de vista médico-sanitário. O exame parasitológico das fezes, de 83 pessoas, realizado por meio de quatro métodos, pode ser considerado como dotado de razoável amplitude para estabelecer diagnósticos. Ocorreu encontro de cistos de protozoários e de ovos de helmintos de múltiplos tipos, até mesmo em expressivas porcentagens, merecendo destaque a muito freqüente presença de Blastocystis hominis (57,8 por cento), como também o encontro de Cryptosporidium sp (3,6 por cento) e de Cyclospora cayetanensis (10,8 por cento), comentado especificamente. O verificado demonstra que tais índios vivem em ambiente onde prevalecem más condições higiênicas, em especial, facilitador da disseminação de protozoários e helmintos pelo contato com o solo ou ingestão de água e alimentos contaminados.

Occurrences of intestinal parasitosis in Indians of the Mapuera community (Oriximiná, State of Pará, Brazil) were evaluated. Within the context of group assessment, this study makes a contribution towards adequate knowledge of this subject, which is significant from a medical-sanitary point of view. Parasitological examination of feces from 83 individuals, performed using four different methods, could be considered to have reasonable amplitude for establishing diagnoses. Protozoan cysts and helminth eggs of many types were found, even with significant percentages. The frequent presence of Blastocystis hominis (57.8 percent), along with findings of Cryptosporidium sp (3.6 percent) and Cyclospora cayetanensis (10.8 percent), deserved highlighting with specific comments. The findings show that these Indians live in an environment in which poor hygiene conditions prevail. In particular, these facilitate the dissemination of protozoa and helminths through contact with the soil or through intake of contaminated water and food.

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.

Uma avaliação sobre a eficácia do método CSF no diagnóstico de helmintíases intestinais / An evaluation of the efficacy of the CSF method for diagnosing intestinal helminthiases

O método CSF, recentemente proposto para diagnóstico de helmintíases intestinais foi comparado com outros (direto; Faust e cols; sedimentação espontânea em água; Kato-Katz) habitualmente usados com essa finalidade. Houve desempenho satisfatório, revelando que tal técnica pode ser adotada em tarefas para diagnóstico ou análise epidemiológicas.

The recently proposed CSF method for diagnosing intestinal helminthiases was compared with the other methods (direct; Faust et al.; spontaneous sedimentation in water; and Kato-Katz) that are routinely for this purpose. The CSF method performed satisfactorily, thus showing that this technique can be adopted for use in diagnoses or epidemiological analyses.

Survival of Trypanosoma cruzi in sugar cane used to prepare juice / Avaliação da sobrevida de Trypanosoma cruzi em cana de açúcar utilizada no preparo do caldo

Chagas disease can be transmitted to man by many different means, including contact with infected triatomine feces, blood transfusion, laboratory accidents, organ transplants, and congenital or oral routes. The latter mode has received considerable attention recently. In this assay, we evaluate the survival of Trypanosoma cruzi contaminating sugar cane used to prepare juice, as well as the viability and capacity for infection by the parasite after recovery. Thirty triatomines were contaminated with T. cruzi Y strain and 45 days later pieces of sugar cane were contaminated with the intestinal contents of the insects. The pieces were ground at different intervals after contamination (time = 0, 1, 4, 6, 12 and 24 hours) and the juice extracted and analyzed. Different methods were used to show T. cruzi in the juice: direct analysis, hematocrit tube centrifugation and QBC, and experimental inoculation in 47 female BALB/c mice (five control mice and seven mice for each interval examined (five inoculated orally and two intraperitoneally). Positive results were found using the direct analysis and QBC methods for juice prepared up to 12 hours after initial contamination. However, by the centrifugation technique, positivity was found only up to four hours after contamination of the sugar cane. Inoculated animals showed parasitemia during a 14 day observation period, demonstrating the high survival rate of T. cruzi in sugar cane.

A doença de Chagas pode ser transmitida ao homem através de vários mecanismos: fezes de triatomíneo infectado; transfusão sangüínea; acidente em laboratório; transplante de órgão; vias congênita ou oral convindo salientar que esta última tem motivado ocorrências recentemente. Neste estudo procuramos avaliar a sobrevida de Trypanosoma cruzi presente em cana de açúcar contaminada com o parasita, utilizada no preparo do caldo e, também, a viabilidade e a capacidade de infecção do parasita depois de ser recuperado. Trinta triatomíneos foram contaminados com a cepa Y de T. cruzi; após 45 dias realizamos a contaminação de pedaços de cana de açúcar com o conteúdo intestinal dos insetos. Estes pedaços foram moídos em diferentes tempos: no início (tempo 0) e após 1, 4, 6, 12 e 24 horas da contaminação e o caldo extraído foi analisado por diferentes métodos: direto, centrifugação em tubo de hematócrito, QBC. Este caldo contaminado foi inoculado em 47 camundongos machos BALB/c, sendo cinco controles (com caldo de cana limpo) e sete para cada tempo estudado (cinco inoculados pela via oral e dois pela intraperitoneal). Na análise direta e no QBC obtivemos resultados positivos até 12 horas e, na centrifugação, ocorreu positividade somente até as quatro horas. As parasitemias dos animais inoculados foram todas positivas em um período de 14 dias de observação, demonstrando alto grau de sobrevivência do T. cruzi na cana de açúcar.

Identification of Cryptosporidium spp. oocysts in fecal smears stained with Heidenhain's iron hematoxylin

There is no paucity of methods for diagnosing Cryptosporidium spp. infection. The merits of immunoassays notwithstanding, microscopic identification of Cryptosporidium spp. oocysts in fecal samples remains an important diagnostic procedure. It owes the persistence of its use to such characteristics as dispensing with expensive equipment and kits, requiring only basic laboratory facilities, and having a low probability of false positive results when permanent slides are prepared, which can be re-examined in case of doubt. Cryptosporidium spp. oocysts can be readily identified in fecal smears prepared according to a regressive iron hematoxylin staining technique. The number of steps and their duration, as well as costs, were reduced to a minimum without loss of image quality and permanence of the preparations

Blastocistose: controvérsias e indefinições / Blastocystosis: controversy and indefinedness

Blastocistose é a infecçäo causada pelo Blastocystis hominis. Está relacionada com várias controvérsias e indefinições, sem dúvida muito importantes sobretudo pelas implicações médico-assistenciais que suscitam. A propósito, pendência expressiva diz respeito à patogenicidade do referido protozoário, que precisa ser categoricamente definida. Ao lado dessa particularidade outros assuntos exigem elucidações através de pesquisas bem conduzidas, para que a blastocistose fique devidamente situada no contexto da saúde pública. Aspecto também digno de atençäo é o diagnóstico pelo exame parasitológico de fezes, necessariamente executável por meio de métodos adequados, como o direto e os permanentes, exemplificados pelos que usam a a hematoxilina férrica ou a tionina. O emprego de técnicas impróprias propicia resultados falsos-negativos, conturbando o aconselhável bom conhecimento da real participaçäo do microrganismo em questäo

Elevada porcentagem de blastocistose em escolares de São Paulo, SP / Blastocystosis: a high proportion of cases found in schoolchildren of São Paulo, State of São Paulo, Brazil

Em exame parasitológico de fezes de 227 alunos de escola pública de São Paulo (SP), encontramos 87 (38,3 por cento) positivas para Blastocystis hominis. A blastocistose ainda suscita controvérsias e indefinições, merecedoras de esclarecimentos sobretudo para evitar contratempos no âmbito da saúde pública e das atenções médico-assistenciais.