Maurício Lima Barreto

Sensilidade e especificidade da leitura da cicatriz vacinol do BCG [Sensitivity and specificity of the BCG scar reading]

OBJECTIVEnTo validate the BCG scar as a marker of BCG vaccination status.nnnMETHODSnA cross-sectional survey was carried out among 53,348 schoolchildren aged 6-14 years who underwent BCG scar examination as part of a large BCG vaccine trial taking place in the city of Manaus, Brazil. Results of BCG scar reading were compared with information on vaccine status of their vaccination cards or provided by parents or guardians. Double-reading was performed in a sub-sample. Data analysis was conducted using Stata 7 and Kappa coefficient.nnnRESULTSnOf 52,348 schoolchildren studied, vaccine status information from parents/guardian letters was available for 29,254 and from vaccination cards for 4,947. There was found a high agreement between the double-readings of the scars (Kappa=0.81). When the agreement between letter and card information was the gold standard, the sensitivity of BCG scar readings was 96.6% (95%CI 96.0-97.1) and the specificity was 71.1% (95%CI 55.7-83.7). The sensitivity was 96.1%, 97.3% and 95.3% for children vaccinated up to one month of age, four months and one year, respectively.nnnCONCLUSIONSnSensitivity and specificity did not show an association with the childs age at the scar reading. BCG scar was a good marker of BCG vaccination status regardless of age - from the first years of life up to 14 years old.OBJETIVO: Validar a utilizacao da cicatriz vacinal de BCG como um indicador de vacinacao. METODOS: Foi realizado um estudo transversal em 52.348 escolares, entre 6 e 14 anos de idade, que possuiam exame de cicatriz vacinal do BCG e que participaram de um ensaio clinico randomizado e controlado na cidade de Manaus, Brasil. Os dados da leitura da cicatriz vacinal foram comparados com a informacao sobre a vacinacao passada fornecida pelos cartoes vacinais ou informacao dos responsaveis. Em uma subamostra foi realizada leitura dupla com calculo do coeficiente Kappa. Para analise dos dados utilizou-se o Stata 7. RESULTADOS: Do total de 52.348 escolares estudados, 29.254 possuiam informacao sobre cicatriz vacinal coletada por meio de carta aos pais, e 4.947 possuiam historia de vacinacao coletada pelo cartao de vacinas. Observou-se elevada concordância entre a dupla leitura de cicatriz vacinal (Kappa =0,81). A sensibilidade da leitura de cicatriz vacinal foi 96,6% (95% IC 96,0-97,1) e a especificidade foi 71,1% (95% IC 55,7-83,7) quando o padrao ouro utilizado foi a concordância entre a carta aos pais e a informacao do cartao de vacinas. A sensibilidade foi de 96,1%, 97,3% e 95,3% para criancas vacinadas ate um mes de idade, ate 4 meses e ate um ano de idade, respectivamente. CONCLUSOES: Os valores encontrados para sensibilidade e especificidade foram independentes da idade da realizacao da leitura de cicatriz vacinal. O exame da cicatriz vacinal mostrou ser um bom indicador para avaliar a situacao vacinal referente ao BCG.

Symptomatic dengue infection during pregnancy and the risk of stillbirth in Brazil, 2006–12: a matched case-control study

BACKGROUNDnMaternal infections during pregnancy can increase the risk of fetal death. Dengue infection is common, but little is known about its role in fetal mortality. We aimed to investigate the association between symptomatic dengue infection during pregnancy and fetal death.nnnMETHODSnWe did a nested case-control study using obstetrician-collected data from the Brazilian livebirth information system (SINASC), the mortality information system (SIM), and the national reportable disease information system (SINAN). We identified all pregnancies ending in stillbirth and a random sample of livebirths between Jan 1, 2006, and Dec 31, 2012. We did linkage to determine which mothers were diagnosed with dengue infection during pregnancy. By use of stillbirths as cases and a sample of matched livebirths as a control, we calculated matched odds ratios (mORs) using conditional logistic regression adjusted for maternal age and education.nnnFINDINGSn275 (0·2%) of 162u2008188 women who had stillbirths and 1507 (0·1%) of 1u2008586u2008105 women who had livebirths were diagnosed with dengue infection during pregnancy. Symptomatic dengue infection during pregnancy almost doubled the odds of fetal death (mOR 1·9, 95% CI 1·6-2·2). The increase in risk was similar when analyses were restricted to laboratory-confirmed cases of dengue infection (1·8, 1·4-2·4). Severe dengue infection increased the risk of fetal death by about five times (4·9, 2·3-10·2).nnnINTERPRETATIONnSymptomatic dengue infection during pregnancy is associated with an increased risk of fetal death. We recommend further epidemiological and biological studies of the association between dengue and poor birth outcomes to measure the burden of subclinical infections and elucidate pathological mechanisms.nnnFUNDINGnBrazilian National Council for Scientific and Technological Development, Horizon 2020.