The role of latex agglutination test for the etiological diagnosis of pleural effusion in children and adolescents.

INTRODUCTION: The etiological diagnosis of pleural effusion is a difficult task because the diagnostic tools can only establish a definitive etiological diagnosis in at most 76% of cases. OBJECTIVES: To verify the diagnostic accuracy of the latex agglutination test (LAT) for the etiological diagnosis of pleural effusions caused by Streptococcus pneumoniae and Haemophilus influenzae type b. METHODS: After thoracocentesis, paired fresh samples of pleural fluid from 418 children and adolescents were included in this investigation. They were tested blindly and simultaneously through counterimmunoelectrophoresis (CIE) and LAT for both bacteria. Sensitivity, specificity, predictive values and likelihood ratios (LR) were calculated taking CIE as a reference standard. RESULTS: The sensitivity and specificity of LAT was 100% (95% confidence interval, 94.4%-100%) and 83.3% (95% confidence interval, 79.0%-87.0%), respectively, whereas the positive (calculated from Bayes' theorem) and negative predictive values were, respectively, lower than 1% and 100% (95% confidence interval, 98.8%-100%). Positive and negative LR were 6.0 (95% confidence interval, 4.7-7.6) and zero, respectively. CONCLUSIONS: Our results suggest that LAT is a useful tool for the etiological diagnosis of pleural effusion. It is a reliable, rapid, simple to perform and shows an excellent yield in our studied population, helping to prescribe appropriate antibiotics for this clinical condition.

Characterization of an astrovirus genotype 2 strain causing an extensive outbreak of gastroenteritis among Maxakali Indians, Southeast Brazil.

BACKGROUND: Human astroviruses (HAstVs) are a common cause of sporadic diarrhea in children but large outbreaks occur in children's day care centers, schools and in homes for the elderly. OBJECTIVES: To report a large outbreak of acute gastroenteritis that occurred in January 2004 among Indians from the Maxakali Reserve in the State of Minas Gerais, Brazil. STUDY DESIGN: Fecal samples from 46 Maxakali patients were collected and tested for a range of enteric pathogens. HAstVs was detected by EIA and strains were confirmed by RT-PCR and typed by direct sequencing. Clinical information was collected. RESULTS: The illness which affected more than 100 children under 6 years of age was characterized by watery diarrhea, fever and vomiting. HAstV-2 was the sole enteropathogen detected in 26 (56%) of 46 samples analyzed by EIA and/or RT-PCR. The 17 positive samples sequenced were identical in a 348bp region used for phylogenetic analysis and were classified as genotype 2. CONCLUSIONS: This is the first description of an outbreak of HAstV-2 gastroenteritis in a population of Brazilian Indians. The magnitude of the outbreak and the severity of the disease underscore the need to better understand the epidemiology of astrovirus and other enteric agents in these populations.

Clinical and laboratorial evidence of Rickettsia felis infections in Latin America.

After the discovery and initial characterization of Rickettsia felis in 1992 by Azad and cols, and the subsequent first description of a human case of infection in 1994, there have been two communications of human rickettsiosis cases caused by Rickettsia felis in Latin America. The first one was published in 2000 by Zavala-Velazquez and cols in Mexico. In 2001 Raoult and cols described the occurrence of two human cases of Rickettsia felis rickettsiosis in Brazil. In the present discussion these two articles were compared and after the description of the principal signs and symptoms, it was concluded that more studies are needed with descriptions of a greater number of patients to establish the true frequency of the clinical signs and symptoms present in Rickettsia felis rickettsiosis.

Clinical and laboratorial evidence of Rickettsia felis infections in Latin America

Depois da descoberta e caracterização inicial da Rickettsia felis em 1992 por Azad e cols, e à descrição subseqüente do primeiro caso de infecção humana em 1994, houveram duas comunicações de rickettsioses causadas por Rickettsia felis na América Latina. A primeira foi feita por Zavala-Velazquez e cols em 2000 no México. Em 2001, Raoult e cols descreveram a ocorrência de dois casos humanos de rickettsiose por Rickettsia felis no Brasil. Na presente discussão, esses dois artigos foram comparados, e depois da descrição dos principais sinais e sintomas, conclui-se que outros estudos são necessários, com a participação de um maior número de pacientes, para se estabelecer a verdadeira freqüência dos sinais clínicos e sintomas presentes nas rickettsioses por Rickettsia felis.

Spotted fever rickettsiosis in Coronel Fabriciano, Minas Gerais State.

We report cases of spotted fever rickettsiosis in Coronel Fabriciano Municipality of Minas Gerais State, Brazil. The cases occurred in May and June of 2000. During this period there were two deaths among children from an area named Pedreira in a periurban area of this municipality. In a boy who died with clinical manifestations of Brazilian spotted fever, a necropsy revealed the presence of a spotted fever group Rickettsia. The serological results confirm the difficulty in the differential diagnosis of patients with symptoms of rickettsial diseases.

Spotted fever rickettsiosis in Coronel Fabriciano, Minas Gerais State

We report cases of spotted fever rickettsiosis in Coronel Fabriciano Municipality of Minas Gerais State, Brazil. The cases occurred in May and June of 2000. During this period there were two deaths among children from an area named Pedreira in a periurban area of this municipality. In a boy who died with clinical manifestations of Brazilian spotted fever, a necropsy revealed the presence of a spotted fever group Rickettsia. The serological results confirm the difficulty in the differential diagnosis of patients with symptoms of rickettsial diseases

Fatal spotted fever rickettsiosis, Minas Gerais, Brazil.

The emergence and reemergence of a serious infectious disease are often associated with a high case-fatality rate because of misdiagnosis and inappropriate or delayed treatment. The current reemergence of spotted fever rickettsiosis caused by Rickettsia rickettsii in Brazil has resulted in a high proportion of fatal cases. We describe two familial clusters of Brazilian spotted fever in the state of Minas Gerais, involving six children 9 months to 15 years of age; five died. Immunohistochemical investigation of tissues obtained at necropsy of a child in each location, Novo Cruzeiro and Coronel Fabriciano municipalities, established the diagnosis by demonstration of disseminated endothelial infection with spotted fever group rickettsiae. The diagnosis in the two fatal cases from Coronel Fabriciano and the surviving patient from Novo Cruzeiro was further supported by immunofluorescence serologic tests.

[Emerging and reemerging rickettsiosis in an endemic area of Minas Gerais State, Brazil]. / Rickettsioses emergentes e reemergentes numa região endêmica do Estado de Minas Gerais, Brasil.

This article describes a serological survey for rickettsiosis in the county of Novo Cruzeiro, Minas Gerais State, Brazil, in 1998, testing schoolchildren and dogs. Sera included 331 samples from schoolchildren from an endemic area and 142 samples from schoolchildren from a non-endemic area in the county. All children examined were healthy and had not reported clinical symptoms of Brazilian spotted fever prior to the serological survey. Some 35 children in the endemic area were reactive to Rickettsia rickettsiiby indirect fluorescent antibody (IFA) with a titer of 1:64, corresponding to 10.6%. Sera from 73 dogs were tested, showing seroreactivity (IFA 1:64) to Rickettsia rickettsi, Ehrlichia chaffeensis, and Ehrlichia canisin 3 (4.11%), 11 (15.07%), and 13 (17.81%), respectively. The results in schoolchildren and the presence of canine seroreactivity to Ehrlichiaspecies that are potentially pathogenic to humans suggests the risk of transmission of other Rickettsiaein the study area.

Rickettsioses emergentes e reemergentes numa regiäo endêmica do Estado de Minas Gerais, Brasil / Emerging and reemerging rickettsiosis in an endemic area of Minas Gerais State, Brazil

O trabalho descreve um inquérito sorológico para rickettsioses em escolares e cäes de Novo Cruzeiro, Minas Gerais, Brasil, em 1998. Trezentos e trinta e um escolares pertenciam a uma área endêmica e 142 a uma área näo endêmica do município. Trinta e nove (10,1 por cento) soros foram reativos à Reaçäo de Imunofluorescência Indireta (RIFI) para Rickettsia rickettsiino título de 1:64, sendo que dentre esses reativos, 35 eram de estudantes de escolas de área endêmica. Dentre os 73 cäes analisados quanto à presença de anticorpos anti R. rickettsii, anti Ehrlichia chaffeensise anti Ehrlichia canisà RIFI no título de 1:64, 3 (4,11 por cento), 11 (15,07 por cento) e 13 (17,81 por cento) desses animais foram reativos respectivamente aos antígenos testados. Conclui-se que, a sororeatividade para R. rickettsiiem indivíduos sadios sem história prévia de febre maculosa brasileira, uma doença marcante por sua alta letalidade, e a presença de sororeatividade para Ehrlichiacom potencial patogênico para o homem em cäes, nos leva a indagar sobre a transmissäo ao homem de outras espécies da família Rickettsiae na área estudada

Rickettsia felis in Ctenocephalides spp. fleas, Brazil.

In June 2000, suspected cases of Brazilian spotted fever (BSF) occurred in Coronel Fabriciano Municipality, Minas Gerais State, Brazil. Pooled fleas collected near two fatal cases contained rickettsial DNA. The nucleotide sequence alignment of the 391-bp segment of the 17-kDa protein gene showed that the products were identical to each other and to the R. felis 17-kDa gene, confirming circulation of R. felis in Brazil.

Utilizaçäo do antígeno prostático específico (PSA livre/total), como marcador tumoral no diagnóstico de câncer de próstata e hiperplasia benigna prostática / Use of PSA (free and total) as tumoral marker in the diagnosis of prostate cancer and prostatic benign hiperthophy

No Brasil, calcula-se que em cada dez homens vá desenvolver um quadro histológico de hiperplasia benigna prostática (HBP)ou um carcinoma prostático (CaP). Estimativas recentes indicam que o CaP é a terceira causa de óbitos entre todos os tipos de neoplasias, e que, após os 75 anos de idade, esses índices atingem o primeiro lugar. O Ministério da Saúde, já inclui o CaP como problema de Saúde Pública. Considera-se, que se fossem feitos exames preventivos, cerca de 10.000 mortes ao ano, seriam evitadas, no Brasil. Essa alta letalidade se deve ao faro de que a doença näo apresenta sintomas nos estágios iniciais, quando seria mais facilmente tratável. O PSA é uma glicoproteína produzida pelo tecido prostático (benigno ou maligno, assim como em metástases). Ral característica permite defini-lo como o mais importante marcador tumoral de CaP. No presente estudo, foram realizadas determinaçöes dos níveis séricos de PSA Livre e Total em 630 pacientes do sexo masculino, provenientes do SAMOC/FUNED e hospitais conveniados com as Diretorias Regionais de Saúde de Minas Gerais e Sistema Unico de Saúde de Minas Gerais. Os pacientes selecionados foram distribuídos inicialmente em 6 grupos, de acordr com a faixa etária: 30-40 anos (13/630), 41-50 anos (76/630), 51-60 anos (82/630), 61-70 anos (89/630), acima de 70 anos (68/630) e sem informaçäo (302/630). Desses, 89,5 porcento apresentaram PSA Total até 4 ng/ml; 8,5 porcento, na faixa de 4-10 ng/ml e em 2 porcento dos casos, PSA Total superior a 10 ng/ml. Objetivando triar os pacientes suspeitos (66/630) quanto à relaçäo PSA Livre/otal, utilizou-se o valor de corte 18 porcento. Em 41 porcento (27/66) deles, a razäo PSA L/T foi superior a 18 porcento (sugestiva de HBP) e em 59 porcento (39/66) obteve-se relaçäo PSA L/T inferior a 18 porcento (indicativo de CaP). A maior incidência de casos com PSA Total superior a 10 ng/ml foi observada na faixa etária entre 61-70 anos. A utilizaçäo do PSA (Livre e Total) tem obtido êxito na indicaçäo diagnóstica (CaP e HBP) e início precoce do tratamento

Atividade da desidrofenase Lactica no liquido cefalorraquiano como indicador de meningite purulenta / Lactic dehydrogenase activity in cerebrospinal fluid for the presumed diagnosis of bacterial meningitis

Os autores realizaram um estudo prospectivo em 121 crianças de 3 meses a 14 anos de idade, com o objetivo de avaliar a ativiade da Desidrogenase Lactica (DHL) no liquido cefalorraquidiano (LCR) para o diagnostico presuntivo de meningite purulenta. Em 74 crianças, a cultura e/ou contraimunoeletroforese e/ou Teste de aglutinaçao de particulas de Latex identificaram os seguintes germes: H.influenzae b, S.pneumoniae e N.meningitidis B e C. O grupo controle foi constituido por 47 crianças com resultados negativos a estes procedimentos alem de apresentarem quimiocitologia normal do LCR. Os exames laboratoriais foram realizados por cinco tecnicos, de forma independente e "cega".Os resultados da DHL no presente estudo foram: sensibilidade de 91,8% (intervalo de confiança a 95%,82,9% - 97,8%),especificidade de 59,5% (intervalo de confiança a 95%,43,5% - 74,5%), valor preditivo positivo de 78,1% (intervalo de confiança a 95%,67,1% - 87,1%) e valor preditivo negativo de 82,3% (intervalo de confiança a 95%,65,3%- 93,3%). Diante dos resultados obtidos os autores admitem que a verificaçao da atividade da DHL no LCR tem pouco valor para o diagnostico de meningite purulenta.