Real-time (RT)-PCR increases diagnostic yield for bacterial meningitis and is ideal for incorporation into routine surveillance in a developing country. We validated a multiplex RT-PCR assay for Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae in Brazil. Risk factors for being culture-negative, RT-PCR positive were determined. The sensitivity of RT-PCR in cerebrospinal fluid (CSF) was 100% (95% confidence limits, 96.0%–100%) for N. meningitidis, 97.8% (85.5%–99.9%) for S. pneumoniae, and 66.7% (9.4%–99.2%) for H. influenzae. Specificity ranged from 98.9% to 100%. Addition of RT-PCR to routine microbiologic methods increased the yield for detection of S. pneumoniae, N. meningitidis, and H. influenzae cases by 52%, 85%, and 20%, respectively. The main risk factor for being culture negative and RT-PCR positive was presence of antibiotic in CSF (odds ratio 12.2, 95% CI 5.9-25.0). RT-PCR using CSF was highly sensitive and specific and substantially added to measures of meningitis disease burden when incorporated into routine public health surveillance in Brazil.

The evidence gathered during this study provides estimates of carriage prevalence in Brazilian adolescents, showing an unusually high dominance of serogroup C. These results have important implications in future strategies to optimize the impact of the current meningococcal C vaccination program in Brazil.

Polysaccharide vaccine did not affect carriage nor interrupt transmission of an epidemic strain.

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Bacterial meningitis (BM) is a severe disease and still represents a serious public health problem with high rates of morbidity and mortality . Additionally, there was a reduction in the number of Hib isolates in the post-vaccination (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008) compared to the pre-vaccination (1990-1999) period, i.e., 98% of the Hi strains serotyped by IAL during pre-vacci ne period were serotype b while only 59% were Hib in the postvaccine. Furthermore, there was an increase from 1% to 19% Keywords: Bacterial meningitis, molecular diagnosis, real time PCR. rESUMO A meningite bacteriana (MB) é uma doença grave e ainda representa um sério problema de saúde pública, com altas taxas de morbidade e mortalidade. Os casos mais comuns de MB em todo o mundo, principalmente no Brasil, tem sido causados por Neisseria meningitidis, Streptococcus pneumoniae e Haemophilus influenzae tipo b. Cultura bacteriana é a técnica padrão-ouro para a confirmação de MB, mas cerca de 50% dos casos suspeitos não são confirmados por cultura, devido a problemas relacionados ao transporte inadequado e semeadura ou antibioticoterapia prévia. Métodos imunológicos apresentam baixa sensibilidade e têm possibilidade de reações cruzadas. PCR em tempo real (qPCR) é uma técnica molecular e tem sido utilizada com êxito para o diagnóstico de MB no Instituto Adolfo Lutz, em São Paulo, Brasil, desde 2007. A incorporação da qPCR na rotina de vigilância em Saúde Pública em nosso estado resultou na diminuição de 50% dos casos de MB indeterminadas. Nossos esforços estão focados na implementação da qPCR na rotina diagnóstica de MB em todo o Brasil.Palavras-Chave: Meningite bacteriana, diagnóstico molecular, PCR em tempo real.