Enrichment culture of CSF is of limited value in the diagnosis of neonatal meningitis

Neonatal meningitis is difficult to diagnose due to the subtle and nonspecific symptoms in neonates, and confirmation requires cerebrospinal fluid examination (CSF) [1]. Gram stain, culture of CSF directly onto agar plates, and broth enrichment culture are well established methods for diagnosing bacterial meningitis [2–5]. Other methods under evaluation include use of bacterial polymerase chain reaction combined with DNA sequencing [6]. The aim of CSF broth enrichment culture is to facilitate the isolation of damaged organisms and to recover those present in small numbers [7, 8]. The exact origin of enrichment culture is unknown [9]. Beijerinck and Winogradski are believed to be the first to recommend enrichment techniques [10]. We previously reported on the utility of various microbiology tests for the diagnosis of bacterial meningitis in the newborn [7]. We showed that enrichment cultures (inoculation of CSF into a brain-heart infusion broth incubated for 48 hrs) when performed on all lumbar puncture specimens are often falsely positive, because the prevalence of true bacterial meningitis is low in neonatal intensive care units and the test lacks specificity. We suggested that enrichment culture should be confined to settings where the prevalence of bacterial meningitis was higher, such as in samples with raised CSF white cell count (WCC), where organisms are seen on the Gram stain or where pathogens may be difficult to grow such as when babies have already received antibiotics. The aim of our current study was to assess the performance of enrichment culture when performed on CSF samples selected on the basis of a raised WCC of ≥30 /mm3

Doença meningocócica: comparação entre formas clínicas Meningococcal disease: comparison between clinical forms

Visando avaliar formas clínicas da doença meningocócica, foram revistos 201 casos diagnosticados como doença meningocócica, em Hospital Universitário da Universidade Federal Fluminense; durante o período de 1971 a 1996, dos quais 185 preencheram os critérios de inclusão. A caracterização clínico-laboratorial permitiu reagrupá-los nas formas de doença meningocócica com meningite, 18%, meningite e septicemia, 62%, e septicemia, 20%. Dados epidemiológicos disponíveis não diferenciaram formas clínicas. Na meningite meningocócica foi significativamente maior: tempo de história clínica; freqüência de manifestações neurológicas; e positividade da bacterioscopia, cultura e teste do látex no líquor. Na septicemia menigocócica, houve predomínio significativamente de: choque; letalidade e níveis maiores de tempo parcial de tromboplastina. Septicemia meningogócica e septicemia com meningite se diferenciaram da meningite meningocócica quanto a: tempo de história clínica; ocorrência de sinais neurológicos focais; coagulação intravascular disseminada e artrite. Dados clínico-laboratoriais levam a admitir meningite como forma localizada de doença meningocócica, e septicemia com meningite e septicemia como variações de gravidade da forma sistêmica da doença.<br>In order to asses the clinical forms of meningococcal disease, we reviewed 201 cases diagnosed as meningococcal disease in the University Hospital of the Fluminense Federal University in Rio de Janeiro, 185 of which met the inclusion criteria. Clinical and laboratorial characterization allowed for grouping of the cases as follows: meningococcal meningitis, 18%; meningitis with septicemia, 62%; and septicemia, 20%. Available epidemiological data did not differentiate clinical forms. The following were significantly greater in meningococcal meningitis: duration of clinical history; frequency of neurological manifestations; positive bacterioscopy; culture and latex test in cerebrospinal fluid. The following were significantly predominant in septicemia: shock; fatal outcome and higher partial thromboplastin time. Septicemia and meningitis with septicemia were differentiated from meningococcal meningitis in the following: duration of clinical history; occurrence of focal neurological signs; disseminated intravascular coagulation; and arthritis. Clinical and laboratory data lead us to admit meningococcal meningitis as a localized form of Meningococcal disease, and meningitis with septicemia and septicemia as variations in severity of the systemic form of the disease