Histoplasmose residual dos pulmões e linfonodos broncopulmonares em necropsias realizadas em Uberaba, MG

Foram estudados pulmões e linfonodos broncopulmonares de 121 necrópsias seqüenciadas de adultos em Uberaba (MG), no período de 1992/1993, identificando-se nódulos e/ou linfonodos calcificados em 39 (30. 7%) casos. Na intimidade destas estruturas calcificadas detectaram-se fungos com morfologia compatível com Histoplasma capsulatum em 27 (69,2%) das 39 necrópsias; a pesquisa de bacilo-álcool- ácido-resistente através da técnica de Fite-Faraco foi negativa em todos os casos. Concluiu-se que em Uberaba a maioria dos nódulos e/ou linfonodos pulmonares calcificados encontrados em necrópsias está relacionada à infecção por Histoplasma capsulatum, levantando a possibilidade de tratar-se de uma área endêmica de histoplasmose, informação importante para o diagnóstico desta micose sistêmica em imunodeprímidos.

Estudo longitudinal sobre portador são de Staphylococcus aureus em alunos de um curso de auxiliar de enfermagem

Este trabalho objetivou conhecer o grau de colonização pelo Staphylococcus aureus e a evolução do estado de portador são em alunos de um curso de Auxiliar de Enfermagem, durante a formação profissional. Participaram 42 alunos, dos quais foram colhidas amostras da cavidade nasal e mãos (direita e esquerda) em seis diferentes momentos da formação. Do total de alunos, 19 (45,2%) comportaram-se como portadores ocasionais, 12 (28,6%) como intermitentes, 6 (14,3%) como persistentes e 5 (11,9%) como não portadores, demonstrando que a colonização não aumentou com o decorrer do curso. Dos alunos, 24 (57,1%) referiram não terem desenvolvido atividades relacionadas à enfermagem antes e/ou durante o curso e 18 (42,9%) referiram exercê-las como atendentes.

A longitudinal study on enteropathogenic infections of livestock in Trinidad

A longitudinal study was conducted on selected livestock farms to determine the prevalence of enteropathogens in diarrhoeic and non-diarrhoeic animals. The enteropathogens assayed from faecal samples and rectal swabs were bacteria (Escherichia coli, Campylobacter spp. Salmonella spp. and Yersinia enterocolitica), parasites (coccidia, gastrointestinal nematodes and Cryptosporidium spp.) and viruses (group A rotavirus and parvovirus). The prevalence of the enteropathogens in various animal species was related to age and month of the year. Generally, younger animals presented a higher prevalence of infection by enteropathogens than older animals while most infections occurred between the months of January and April.

Clonal structure of Trypanosoma cruzi Colombian strain (biodeme Type III): biological, isoenzymic and histopathological analysis of seven isolated clones

The clonal structure of the Colombian strain of Trypanosoma cruzi, biodeme Type III and zymodeme 1, was analyzed in order to characterize its populations and to establish its homogeneity or heterogeneity. Seven isolated clones presented the basic characteristics of Biodeme Type III, with the same patterns of parasitemic curves, tissue tropism to skeletal muscle and myocardium, high pathogenicity with extensive necrotic-inflammatory lesions from the 20th to 30th day of infection. The parental strain and its clones C1, C3, C4 and C6, determined the higher levels of parasitemia, 20 to 30 days of infection, with high mortality rate up to 30 days (79 to 100%); clones C2, C5 and C7 presented lower levels of parasitemia, with low mortality rates (7.6 to 23%). Isoenzymic patterns, characteristic of zymodeme 1, (Z1) were similar for the parental strain and its seven clones. Results point to a phenotypic homogeneity of the clones isolated from the Colombian strain and suggest the predominance of a principal clone, responsible for the biological behavior of the parental strain and clones.

Emprego de pote fumígeno para proteção de insetário e sua ação residual contra triatomíneos, em condições de laboratório

Pote fumígeno à base de piretroides e diclorvos foi empregado para desinsetizar um insetário de triatomíneos, contaminado com baratas e formigas. Retirados os triatomíneos durante a aplicação, o produto mostrou-se muito eficiente contra os insetos invasores, eliminando-os completamente em 48 horas. Monitorando-se a ação triatomicida através de frascos sentinelas com adultos, ninfas e ovos de Triatoma infestans, Panstrongylus megistus e Rhodnius neglectus, não se observou ação ovicida, mas sobre os adultos e ninfas até pelo menos 72 horas após a fumigação, no recinto fechado.

Trypanosoma cruzi: susceptibility to chemotherapy with benznidazole of clones isolated from the highly resistant Colombian strain

The present investigation was performed to evaluate the susceptibility of seven clones isolated from the highly resistant Colombian strains, prototype of Biodeme Type III. Seven clones previously obtained, showed a phenotypic homogeneity and high similarity with the parental strain. Eight groups of 30 mice were inoculated with one of seven clones or the parental strain; 20 were treated with benznidazole (100mg/kg/day) and 10 were untreated controls. Cure evaluations were done by parasitological and serological tests and PCR. Cure rates varied from 0% (null) to 16.7%. Correlation between positivity of parasitological and serological tests with positive PCR reached 37%. The results demonstrated the high resistance of the clones, suggesting the predominance of a highly resistant principal clone in this strain. The findings apparently indicate that the possibility of cure is minimal for patients infected with this biodeme; a fact that could affect the control of Chagas' disease through treatment of chronically infected people.

Longitudinal comparison between plasma and seminal HIV-1 viral loads during antiretroviral treatment

This study was designed to investigate the impact of anti-retroviral therapy on both plasma and seminal HIV-1 viral loads and the correlation between viral loads in these compartments after treatment. Viral load, CD4+ and CD8+ T-cell counts were evaluated in paired plasma and semen samples from 36 antiretroviral therapy-naïve patients at baseline and on days 45, 90, and 180 of treatment. Slopes for blood and seminal viral loads in all treated patients were similar (p = 0.21). Median HIV-1 RNA titers in plasma and semen at baseline were 4.95 log10 and 4.48 log10 copies/ml, respectively. After 180 days of therapy, the median viral load declined to 3.15 log10 copies/ml (plasma) and 3.2 log10 copies/ml (semen). At this timepoint 22 patients presented HIV-1 viral load below 400 copies/ml in either plasma or semen, but only 9 had viral loads below 400 copies/ml in both compartments.

Estudo longitudinal e quimioterapia específica em crianças, com doença de Chagas crônica, residentes em área de baixa endemicidade da República Argentina

Apresenta-se a avaliação clinicoepidemiológica de 95 crianças chagásicas crônicas em idades entre 1 e 14 anos moradoras de Santa Fé, Argentina, não tratadas e tratadas com nifurtimox ou benznidazol, com acompanhamento de até 24 anos. Todas tinham vários antecedentes de risco para transmissão do Trypanosoma cruzi: vetorial, congênito e/ou transfusão sangüínea. O diagnóstico da infecção foi feito através de sorologia convencional. O exame clínico foi complementado por eletrocardiograma, radiografias de tórax e, análise de sangue e urina para avaliação das funções hepáticas. No pós-tratamento, utilizaram-se técnicas idênticas às do diagnóstico, sendo que 33 crianças tiveram, também, avaliação parasitológica. Dentre 24 crianças não tratadas, 14 foram controlados por 8 a 24 anos e mantiveram sorologia positiva e o estado clínico inicial. Das 71 crianças tratadas, 49 tiveram acompanhamento de 4 a 24 anos: 14 mantiveram anticorpos anti-Trypanosoma cruzi; 6 resultados discordantes e 29 negativaram a sorologia. Destas, 9 apresentaram oscilações sorológicas, antes da negativação definitiva. A mediana do tempo de negativação pós-tratamento foi, respectivamente, de 3,5 e 8 anos para crianças de 1 a 6 e 7 a 14 anos. A percentagem de soronegativos diminuiu com a idade em que se medicou, desde 75% em <4 anos até 43% em > 9 anos. A intolerância ao tratamento foi de 3,8%. Nenhuma criança modificou seu estado clínico nesta observação.

Yellow fever virus isolated from a fatal post vaccination event: an experimental comparative study with the 17DD vaccine strain in the Syrian hamster (Mesocricetus auratus)

In order to investigate the pathogenicity of the virus strain GOI 4191 that was isolated from a fatal adverse event after yellow fever virus (YFV) vaccination, an experimental assay using hamsters (Mesocricetus auratus) as animal model and YFV 17DD vaccine strain as virus reference was accomplished. The two virus strains were inoculated by intracerebral, intrahepatic and subcutaneous routes. The levels of viremia, antibody response, and aminotransferases were determined in sera; while virus, antigen and histopathological changes were determined in the viscera. No viremia was detected for either strain following infection; the immune response was demonstrated to be more effective to strain GOI 4191; and no significant aminotransferase levels alterations were detected. Strain GOI 4191 was recovered only from the brain of animals inoculated by the IC route. Viral antigens were detected in liver and brain by immunohistochemical assay. Histothological changes in the viscera were characterized by inflammatory infiltrate, hepatocellular necrosis, and viral encephalitis. Histological alterations and detection of viral antigen were observed in the liver of animals inoculated by the intrahepatic route. These findings were similar for both strains used in the experiment; however, significant differences were observed from those results previously reported for wild type YFV strains.

Response to chemotherapy with benznidazole of clones isolated from the 21SF strain of Trypanosoma cruzi (biodeme Type II, Trypanosoma cruzi II)

Susceptibility to chemotherapy with benznidazole was investigated of 5 clones isolated from the 21 SF strain (biodeme Type II, Trypanosoma cruzi II). Swiss mice were infected with the parental strain for each clone and submitted to chemotherapy with benznidazole (100mg/kg/day during 90 days). Treatment determined negativity of the parasitemia. Cure rates were evaluated by parasitological cure tests. Serology was evaluated for treated animals (titers from negative to 1:640) and untreated controls (1:160 to 1:640). Cure rates varied from 30 to 100% for the 5 clones, and were 25% for the parental strain. Results suggested that the variability of response to treatment of the clonal populations of Trypanosoma cruzi II strains is responsible for the high variation in the response to chemotherapy with benznidazole and nifurtimox by strains of this biodeme.

Longitudinal clinical and serological survey of abdominal angiostrongyliasis in Guaporé, southern Brazil, from 1995 to 1999

Abdominal angiostrongyliasis is a zoonotic infection caused by Angiostrongylus costaricensis, a nematode with an intra-vascular location in the mesentery. Our objective was to address several aspects of the natural history of this parasitosis, in a longitudinal clinical and seroepidemiological study. A total of 179 individuals living in a rural area with active transmission in southern Brazil were followed for five years (1995-1999) resulting in yearly prevalence of 28.2%, 4.2%, 10%, 20.2% and 2.8% and incidences of 0%, 5.9%, 8% and 1.5%, respectively. Both men and woman were affected with higher frequencies at age 30-49 years. In 32 individuals serum samples were collected at all time points and IgG antibody reactivity detected by ELISA was variable and usually persisting not longer than one year. Some individual antibody patterns were suggestive of re-infection. There was no association with occurrence of abdominal pain or of other enteroparasites and there was no individual with a confirmed (histopathologic) diagnosis. Mollusks were found with infective third-stage larvae in some houses with an overall prevalence of 16% and a low parasitic burden. In conclusion, abdominal angiostrongyliasis in southern Brazil may be a frequent infection with low morbidity and a gradually decreasing serological reactivity.

Efeito residual de apresentações comerciais dos larvicidas temefos e Bacillus thuringiensis israelensis sobre larvas de Aedes aegypti em recipientes com renovação de água

Avaliou-se o efeito residual do temefos (apresentações comerciais A, B, C) e Bacillus thuringiensis israelensis (D e E) sobre larvas de Aedes aegypti, em recipientes com renovação de água. Utilizaram-se 44 béqueres de 1.000ml (8 para cada apresentação e 4 controles). Em cada béquer introduziram-se diariamente 25 larvas. Após 24 horas, contavam-se as larvas mortas, esvaziavam-se os béqueres até 200ml, repunha-se o volume original e acrescentavam-se novas larvas. A duração do efeito residual máximo (100% de mortalidade) foi: A-19; B-39; C-40; D-8; E-19 dias. A razão de mortalidade permaneceu equivalente entre todos os larvicidas durante 25 dias; B e C mostraram RM 2,40 vezes maior do que E entre 46-95 dias; B, comparado com A, mostrou RM 1,90-7,51 vezes maior entre 26-95 dias. Conclui-se pela maior eficácia de duas apresentações do temefos, mesmo em uma situação epidemiológica de longa exposição ao produto e com renovação de água dos recipientes.

Absence of experimental cross-protection induced by a Trypanosoma cruzi-like strain isolated from bats

This study evaluated the possibility of inoculation and reinoculation with a trypanosomatid isolated from bats that is morphologically, biologically and molecularly similar to Trypanosoma cruzi, to protect against infection by virulent strains. Non-isogenic mice were divided into 24 groups that received from zero to three inoculations of Trypanosoma cruzi-like strain RM1, in the presence or absence of Freund's adjuvant, and were challenged with the VIC or JG strains of Trypanosoma cruzi. Parasitemia and survival were monitored and animals were sacrificed for histopathological analysis. Animals immunized with Trypanosoma cruzi-like strain RM1 presented decreased parasitemia, independently of the number of inoculations or the presence of adjuvant. In spite of this reduction, these animals did not present any protection against histopathological lesions. Severe eosinophilic infiltrate was observed and was correlated with the number of inoculations of Trypanosoma cruzi-like strain RM1. These findings suggest that prior inoculation with this strain did not protect against infection but, rather, aggravated the tissue inflammatory process.

Estabelecimento de metodologia para alimentação de Aedes aegypti (Diptera-Culicidae) em camundongos swiss e avaliação da toxicidade e do efeito residual do óleo essencial de Tagetes minuta L (Asteraceae) em populações de Aedes aegypti

Objetivou-se desenvolver um procedimento de alimentação de fêmeas de Aedes aegypti que não cause estresse em camundongo swiss e avaliar a toxicidade e o efeito residual do óleo essencial de Tagetes minuta L (Asteraceae) em populações de Aedes aegypti. Camundongos anestesiados: um observado tempo de sedação e outro colocado em gaiola para alimentação de fêmeas. Óleo essencial, diluído em acetona, foi utilizado em bioensaios para avaliação das concentrações letais em larvas de Bauru, SP e São José do Rio Preto, SP, respectivamente, sensíveis e resistentes ao temephos. Os dados obtidos foram comparados com a cepa Rockefeller-EUA. O procedimento com camundongos foi aprovado. Não houve diferença entre as populações quanto à susceptibilidade a Tagetes minuta e os ensaios demonstraram CL50 de 0,24, 0,25 e 0,21mL L-1 e CL99,9 em 0,35, 0,39 e 0,42mL L-1, respectivamente, para Rockfeller, Bauru e São José do Rio Preto. Não foi observado efeito residual da solução.