Accuracy of antigen tests for meningococcal meningitis in cerebrospinal fluid: A diagnostic meta-analysis

Objectives: Neisseria meningitidis is one of the major pathogens of meningitis in children worldwide and causes invasive meningococcal disease (IMD), which is a critical illness that mainly presents as meningitis and/or septicemia in children. Identification of N. meningitidis in cerebrospinal fluid (CSF) is the gold standard for the diagnosis of meningococcal meningitis, but antigen tests have advantages such as timely results, relatively low cost, and convenience. Yet, the diagnostic accuracy of antigen tests remains uncertain. Therefore, the aim of this meta-analysis was to evaluate the diagnostic accuracy of antigen tests for N. meningitidis in CSF.Methods: We searched the PubMed, Embase, and Cochrane Library databases for studies evaluating the diagnostic accuracy of antigen tests for N. meningitidis in CSF. We included studies that provided sufficient data to construct a 2 x 2 table on a per-sample basis. To determine the overall sensitivity and specificity of the antigen tests, we used polymerase chain reaction (PCR) as the reference standard and employed the hierarchical summary receiver operating characteristic model.Results: Nine studies with 4533 CSF samples were included. The meta-analysis yielded a pooled sensitivity of 91.2% (95% confidence interval [CI]: 80.0%-100.0%) and a pooled specificity of 93.8% (95% CI: 83.9%-100.0%). A subgroup analysis of 2 studies that reported the outcomes of MeningoSpeed yielded a pooled sensitivity of 93.4% (95% CI: 90.0%-95.8%) and a pooled specificity of 91.9% (95% CI: 88.6%-94.4%). Antigen testing for the N. meningitidis serogroup X had a pooled sensitivity of 92.4% (95% CI: 85.2%-96.2%) and a pooled specificity of 99.2% (95% CI: 78.7%-100.0%).Conclusions: The studied antigen tests had high sensitivity and specificity for the diagnosis of meningococcal meningitis in CSF specimens. Antigen testing could serve as an accurate diagnostic method for assessing patients who have a suspected N. meningitidis infection.