Incidence and risk factors for Dengue virus (DENV) infection in the first 2 years of life in a Brazilian prospective birth cohort.

This study assessed the incidence and risk factors for dengue virus (DENV) infection among children in a prospective birth cohort conducted in the city of Recife, a hyperendemic dengue area in Northeast Brazil. Healthy pregnant women (n = 415) residing in Recife who agreed to have their children followed were enrolled. Children were followed during their first 24 months of age (May/2011-June/2014), before the 2015 Zika virus outbreak. DENV infection was detected by reverse-transcriptase polymerase chain reaction and/or serology (anti-DENV IgM/IgG). The incidence rates per 1000 person-years (py) and its association with risk factors by age bands (0-12, >12-30 months) were estimated through Poisson regression models. Forty-nine dengue infections were detected; none progressed to severe forms. The incidence rates were 107·6/1000py (95% CI 76·8-150·6) and 93·3/1000py (95% CI 56·1-154·4) in the first and second years of age, respectively. Male children (risk ratios (RR) = 2·33; 95% CI 1·09-4·98) and those born to DENV-naïve mothers (RR = 2·42; 95% CI 1·01-5·80) were at greater risk of infection in the first year of age. In the second year, children born to Caucasian/Asian descent skin colour mothers had a threefold higher risk of infection (RR = 3·34; 95% CI: 1·08-10·33). These data show the high exposure of children to DENV infection in our setting and highlight the role of biological factors in this population's susceptibility to infection.

Force of infection of dengue serotypes in a population-based study in the northeast of Brazil.

This study investigated anti-dengue serotype-specific neutralizing antibodies in a random sample of dengue IgG-positive individuals identified in a survey performed in a hyperendemic setting in northeastern Brazil in 2005. Of 323 individuals, 174 (53.8%) had antibodies to dengue virus serotype 1 (DENV-1), 104 (32.2%) to DENV-2 and 301 (93.2%) to DENV-3. Monotypic infections by DENV-3 were the most frequent infection (35.6%). Of 109 individuals aged <15 years, 61.5% presented multitypic infections. The force of infection estimated by a catalytic model was 0.9%, 0.4% and 2.5% person-years for DENV-1, DENV-2 and DENV-3, respectively. By the age of 5 years, about 70%, 30% and 40% of participants were immune to DENV-3, DENV-2 and DENV-1, respectively. The data suggest that infection with DENV-1, -2 and -3 is intense at early ages, demonstrating the need for research efforts to investigate dengue infection in representative population samples of Brazilian children during early infancy.

Staphylococcus aureus bacteraemia: incidence, risk factors and predictors for death in a Brazilian teaching hospital.

The aim of this study was to evaluate the incidence of bloodstream infection due to Staphylococcus aureus and the risk factors for mortality. The design was a two-year retrospective cohort of patients more than one year of age with clinically significant and microbiologically documented bloodstream infection due to S. aureus between January 2000 and December 2001 in a tertiary teaching hospital in midwest Brazil. One hundred and eleven patients were identified with clinically significant and microbiologically confirmed bacteraemia due to S. aureus, accounting for an infection rate of five per 1000 admissions. Nosocomial infections represented 83.8% of cases and meticillin-resistant Staphylococcus aureus (MRSA) accounted for 60.2% of cases. Overall mortality due to S. aureus bacteraemia was 35.1%. Infection due to MRSA, severity of clinical status (severe sepsis or septic shock) and inadequate initial antimicrobial therapy were identified by univariate analysis as predictors of mortality. After Cox regression analysis, severity of clinical manifestations [hazard ratio (HR) 6.86, 95% confidence interval (CI) 3.05-15.43] and inadequacy of antimicrobial therapy (HR 2.27, 95%CI 1.02-5.09) remained as risk factors for mortality. Early diagnosis of bacteraemia should be sought in order to implement adequate treatment before the onset of severe sepsis and septic shock, thus reducing the mortality rate.

Human immunodeficiency virus type 1 and hepatitis C virus co-infection and viral subtypes at an HIV testing center in Brazil.

Human immunodeficiency virus (HIV) testing sites have been recognized recently as potential settings for hepatitis C virus (HCV) screening since both viruses share common routes of transmission. HIV and HCV prevalence, predictors, co-infection rates, and viral subtypes were studied in 592 attendants at an anonymous HIV Counseling and Testing Center in central Brazil. Anti-HIV-1 and -HCV antibodies were screened by ELISA, and Western blots were used to confirm HIV infection. Among HIV-seropositive samples, reverse transcriptase-polymerase chain reaction (RT-PCR) and nested-PCR were used to subtype HIV-1 by the Heteroduplex Mobility Analysis (HMA) and HCV by the line probe assay (INNO-LiPA). HIV and HCV seroprevalence was 3.2% (95% CI 2.0-4.9) and 2.5% (95% CI 1.5-4.0), respectively. Intravenous drug use was the risk factor most strongly associated with both HIV and HCV infections, even in a population with few intravenous drug users (n = 6); incarceration was also associated with HCV. HIV/AIDS-positive sexual partner and homosexual/bisexual behaviors were associated independently with HIV-1. The prevalence of HCV infection among HIV-positive persons was 42% (95% CI 20-66), higher than in HIV-negative persons (1.2%; 95% CI 0.5-2.5). HIV-1 subtype B was identified in the env and gag regions of the genome. HCV subtype 3a predominated among co-infected persons and one HCV subtype 1a was detected. Overall, a similar prevalence of HIV and HCV infections and a higher prevalence of HCV among HIV-positive persons were observed. Integrated HIV and HCV screening at HIV testing sites may represent a unique opportunity to provide diagnosis and prevention strategies at a single visit.

Trends of T. cruzi infection based on data from blood bank screening

Dados de soroprevalencia para doenca de Chagas em primo-doadores de sangue obtidos num estudo seccional foram comparados com estimativas previas obtidas ha 15 anos na mesma populacao no intuito de estudar tendencia temporal da infeccao pelo T.cruzi. Durante o periodo de outubro de 1988 a abril de 1989, 1358 primo-doadores de sangue em seis dos oito bancos de sangue de Goiania-Goias foram rastreados sorologicamente para deteccao de anticorpos anti-T. cruzi pelas tecnicas de hemaglutinacao indireta (IHA) e fixacao de complemento (FC). Os doadores foram entrevistados colhendo-se informacoes sobre idade, sexo, naturalidade, historia de migracao e nivel socio-economico para a estimativa de soroprevalencias especificas. Foi obtida uma prevalencia global de 3,5 por cento (limites de confianca 95 por cento, 2,5-4,5), detectando-se um aumento de prevalencia com a idade ate os 45 anos e posterior decrescimo. Individuos procedentes de zona rural apresentaram taxas de soroprevalencias superiores aquelas obtidas entre os doadores de area urbana (1,8 por cento-16,2 por cento vs. 0 por cento-3,6 por cento). Foi observado um decrescimo de quatro vezes na taxa de prevalencia global quando se comparou os resultados atuais com estimativas obtidas nos estudos anteriores. Duas hipoteses foram sugeridas para explicar a variacao de prevalencia: 1. um efeito "coorte" relacionado ao decrescimo da transmissao em areas

Risk factor and prevalence of antibodies against hepatitis a virus (HAV) in children from day-care centers, in Goiania, Brazil

Um estudo seroepidemiologico para o virus da hepatite A (VHA), investigando os marcadores de infeccao passada (anti-VHA total anti-IgG e IgM) e infeccao recente (anti-VHA IgM), foi realizado entre 1991 e 1992, em criancas de creche de Goiania-Brasil central. Das 310 criancas com idade entre 03 meses e 09 anos, 69,7 por cento mostraram soropositividade ao anti-VHA total, sendo 60 por cento, na faixa etaria entre 1 e 3 anos. A prevalencia do marcador anti-VHA IgM foi de 3,2 por cento visto em idade de 1-4 anos e com distribuicao uniforme nas 10 creches estudadas. Entre as variaveis sociodemograficas estudadas, apenas o tempo de frequencia das criancas nas creches, igual ou superior a um ano, mostrou, em analise multivariada ajustada para idade, um risco de 4,7 vezes maior quando comparado com o periodo de um mes (LC 95 por cento 2,3-9,9)...

Soroepidemiologia da infecçäo pelo vírus da hepatite A em meninos de/na rua de Goiânia-Goiás / Seroepidemiology of hepatitis A virus infection in street children of Goiânia-Goiás

Um estudo soro epidemiológico, para anticorpos contra o virus da hepatite A (anti-VHA total-IgM e IgG), foi realizado no período de 1991-1992, em 397 "meninos de/na rua" em Goiânia. Destes, 313 apresentavam vínculo familiar e desenvolviam, em sua maioria, atividades de trabalho informal, enquanto que 84 nao possuiam vínculo familiar e se encontravam na rua ou em Instituiçoes do Governo Estadual. A taxa média de prevalência foi de 90,4 por cento, variando de 80,0 por cento a 92,9 por cento, sem contudo apresentar diferença estatística significante relativa à idade (7-21). Também nao se evidenciou qualquer diferença quando este grupo foi estratificado para presença ou ausência de vínculo familiar ou mesmo quando analisado em relaçao a outras variáveis sócio-demográficas. Estes dados sugerem que a hepatite A é endêmica na populaçao de baixa condiçao sócio-econômica da regiao e que nesta faixa etária a maioria dos indivíduos já adquiriu a infecçao. Outras investigaçoes em grupos e camadas sociais diferentes sao necessárias a fim de parametrar estratégias vacinais em países subdesenvolvidos.