Measles vaccine: induced specific antibody in normal and undernourished infants

Two hundred and twenty tree children were studied regarding their response to the measles vaccine. The antibody response was measured by hemaglutination inhibition technique. Among the variables studied only the children's age at the time the vaccine was done had influence on the seroconvertion. Sex and nutritional status had no influence on the seroconvertion. A theoric model was designed to find at what age the vaccine had the best effect in preventing mortality. The age predicte was seven months.Foi estudada a indução de anticorpos anti-sarampo em 223 crianças nutridas e desnutridas vacinadas entre 6 e 24 meses e naquelas que permaneceram soronegativas com 1 dose da vacina realizada antes dos 12 meses que foram revacinadas após os 12 meses. A determinação de anticorpos anti-sarampo foi realizada pelas técnicas de inibição da hemaglutinação e de soroneutralização. Observamos que a taxa de soroconversão aumentou progressivamente com a idade, sendo de 43% aos 6 meses e de 80% aos 15 meses. A taxa de soroconversão em crianças marasmáticas foi semelhante à obtida em crianças nutridas, concordando com a literatura que vem demonstrando que crianças desnutridas não apresentam alteração na capacidade de resposta humoral à vacina. Utilizando os dados de mortalidade por sarampo e as taxas de soroconversão à vacina, idealizou-se um modelo hipotético para a avaliação da aplicação da vacina em diferentes idades e suas conseqüências em têrmos de mortalidade, e observou-se que quando a vacina é realizada em idades precoces (6-7 meses) o número de óbito esperado é inferior ao esperado quando a vacina é realizada em idades posteriores (9-11 meses), indicando que a proposta atual do Ministério da Saúde de aplicar dose única aos 9 meses, teoricamente aumentaria o risco de mortalidade. Considerando o número de crianças protegidas com 1 dose de vacina aplicada antes dos 12 meses e o número de crianças protegidas com a revacinação a taxa de soroconversão foi de 84,3%

Inquérito sorológico de sarampo em crianças de 5 a 15 meses de idade, em Curitiba e São José dos Pinhais, Estado do Paraná, Brasil, 1983

A serological survey intended to evaluate the causes of the high incidence of frequent outbreaks of measles in the cities of Curitiba and S. José dos Pinhais, Paraná, shows that of children vaccinated between 7 and 10 months of age, only 44% are protected, whereas in those vaccinated between the 11th and 15th months, the level of protection rises to 65.1%. Samples taken in non-vaccinated children at the 5th, 6th and 7th months of age showed protection level of 56.7%, 28.6% and 14.8% respectively. The children vaccinated during the 7th and 8th months of age had a percentage of protection of 50.8, and those vaccinated from the 9th month on, a percentage of 75.75. The geometric averages of antibody titers are also lower in those vaccinated before 9 months of age as compared to those vaccinated after this age.Inquérito sorológico, realizado para avaliar os motivos da alta incidência e surtos freqüentes de sarampo nas cidades de Curitiba e São José dos Pinhais - Paraná (Brasil), revela que entre 7 e 10 meses de idade só 44% das crianças vacinadas estão protegidas e que entre o 11º e 15º mês o índice de proteção se eleva para 65,1%. As não vacinadas, ao 5º, 6º e 7º mês de idade apresentaram percentuais de proteção de 56,7, 28,6 e 14,8, respectivamente. As crianças que foram vacinadas ao 7º e 8º mês apresentaram percentuais de proteção de 50,8 e as vacinadas a partir do 9º mês, de 75,75%. As médias geométricas dos títulos de anticorpos também foram menores nas vacinadas antes dos 9 meses, em relação às vacinadas a partir desta idade

Molecular epidemiology of the human group A rotavirus in the Paraná State, Brazil

From January/2000 to December/2003, 550 diarrheic fecal samples from the children and adults were collected in several geographical regions of Paraná State, Brazil. The enzyme immunoassay showed 120 (21.8%) samples positive for the group A rotaviruses. One hundred and fourteen samples were genotyped by multiplex-nested-PCR assay. The highest frequency (77.5%) of the positive samples (n=93) was observed in the children under 5 years old. Rotavirus diarrhea was more frequent in the cold and dry seasons of the four evaluated years. The most frequent genotypes were: G1 (50.9%), G4 (9.6%), G9 (7.0%), G2 (1.7%), G3 (0.9%), P[ 8] (71.9%), and P[ 4] (3.5%). The P[ 8] G1 (46.5%) and P[ 8] G4 (9.6%) were the main combinations found to P and G genotypes. The mixed infections, characterized by the rotaviruses with more than one genotype G or P, and nontypeable rotavirus were observed in 8.8, 3.5, and 16.7% of the samples, respectively. The identification of the G9 genotype in the rotavirus strains tested along the four years of studies ratifies the emergency of this genotype also in Paraná State, South region of Brazil, as the worldwide

Rapid, actionable diagnosis of urban epidemic leptospirosis using a pathogenic <i>Leptospira lipL32</i>-based real-time PCR assay

<div><p>Background</p><p>With a conservatively estimated 1 million cases of leptospirosis worldwide and a 5–10% fatality rate, the rapid diagnosis of leptospirosis leading to effective clinical and public health decision making is of high importance, and yet remains a challenge.</p><p>Methodology</p><p>Based on parallel, population-based studies in two leptospirosis-endemic regions in Brazil, a real-time PCR assay which detects <i>lipL32</i>, a gene specifically present in pathogenic <i>Leptospira</i>, was assessed for the diagnostic effectiveness and accuracy. Patients identified by active hospital-based surveillance in Salvador and Curitiba during large urban leptospirosis epidemics were tested. Real-time PCR reactions were performed with DNA-extracted samples obtained from 127 confirmed and 23 unconfirmed cases suspected of leptospirosis, 122 patients with an acute febrile illness other than leptospirosis, and 60 healthy blood donors.</p><p>Principal findings</p><p>The PCR assay had a limit of detection of 280 <i>Leptospira</i> genomic equivalents/mL. Sensitivity for confirmed cases was 61% for whole blood and 29% for serum samples. Sensitivity was higher (86%) for samples collected within the first 6 days after onset of illness compared to those collected after 7 days (34%). The real-time PCR assay was able to detect leptospiral DNA in blood from 56% of serological non-confirmed cases. The overall specificity of the assay was 99%.</p><p>Conclusions</p><p>These findings indicate that real-time PCR may be a reliable tool for early diagnosis of leptospirosis, which is decisive for clinical management of severe and life-threatening cases and for public health decision making.</p></div

Positivity of the <i>lipL32</i> real-time PCR assay according to days after onset of symptoms in suspected cases of leptospirosis.

<p>The bars represent the percentage of positive whole blood samples stratified according to days with symptoms (error bars show the 95% CI). The dashed line shows the geometric mean of the reciprocal MAT titer, in accordance with days with symptoms.</p

Diagnostic performance of the real-time PCR detection assay for confirmed and unconfirmed cases of leptospirosis and control subjects.

<p>Diagnostic performance of the real-time PCR detection assay for confirmed and unconfirmed cases of leptospirosis and control subjects.</p

Standards for Reporting of Diagnostic Accuracy (STARD) flow chart of the 150 suspected leptospirosis cases enrolled in the study.

<p>Patients were selected in two Brazilian cities: Curitiba (A) and Salvador (B).</p