Immunochromatography in CSF improves data on surveillance of S. pneumoniae meningitis in India

Diagnostic accuracy of rapid antigen tests in cerebrospinal fluid for pneumococcal meningitis: a systematic review and meta-analysis

BACKGROUND

Streptococcus pneumoniae is a leading cause of bacterial meningitis worldwide. Conventional microbiological assays take several days and require the use of various drugs for empirical treatment. Rapid antigen tests in cerebrospinal fluid (CSF) may be useful to triage pneumococcal meningitis immediately.

OBJECTIVES

To elucidate whether rapid antigen tests in CSF are useful in the triage of pneumococcal meningitis.

METHODS

Data sourcesCochrane CENTRAL, MEDLINE, EMBASE, World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov databases were searched. Study eligibility criteriaAll types of cohort studies except multiple-group studies, where the sensitivity and specificity of rapid antigen tests in CSF compared with CSF culture can be extracted. ParticipantsPatients with suspected meningitis. TestsRapid antigen tests in CSF. Reference standardsOne or more of the following: blood culture, CSF culture, and polymerase chain reaction in CSF. Assessment of risk of biasThe methodological quality of the included studies was assessed using QUADAS-2. Methods of data synthesisWe used a random-effects bivariate model for the meta-analysis. We conducted a subgroup analysis by dividing studies into types of antigen tests, adults and children, low-income and high-income countries, and with or without exposure to antibiotics before lumbar puncture.

RESULTS

Forty-four studies involving 14 791 participants were included. Most studies had a moderate-to-low methodological quality. Summary sensitivity and specificity were 99.5% (95% confidence interval (CI), 92.4-100%) and 98.2% (95% CI, 96.9-98.9%), respectively. Positive predictive values and negative predictive values at the median prevalence (4.2%) in the included studies were 70.8% (95% CI, 56.6-79.9%) and 100% (95% CI, 99.7-100%), respectively. The diagnostic accuracy was consistent across the various subgroups, except for slightly reduced sensitivity in high-income countries.

CONCLUSIONS

Rapid antigen tests in CSF would be useful in triaging pneumococcal meningitis. Further studies are warranted to investigate the clinical benefit of ruling out pneumococcal meningitis based on the results of rapid antigen tests.

Quadruple valve infective endocarditis presenting with suspected Austrian syndrome: a case report and a case series of quadruple valve infective endocarditis

OBJECTIVES

Austrian syndrome comprises the triad of pneumonia, meningitis, and endocarditis secondary to Streptococcus pneumonia. We present what we believe to be the first reported case of Austrian syndrome with quadruple heart valve involvement and review the literature detailing cases of quadruple valve infective endocarditis.

CASE PRESENTATION AND RESULTS

A case is presented of a patient with radiographic evidence of a left lower lobe pneumonia. Sequential transthoracic followed by transesophageal echocardiogram done to evaluate the presence of a cardiac murmur revealed the presence of quadruple valve vegetations. Multiple blood cultures were persistently negative. The patient went on to develop seizures secondary to proven meningitis. Microbiological diagnosis was eventually established through positive Streptococcus pneumoniae antigen (Alere BinaxNOW®) from cerebrospinal fluid, establishing a presumptive clinical diagnosis of Austrian syndrome. A computerized PubMed search for reports of quadruple valve infective endocarditis and their references was collated. A total of 22 patients were found, including our patient. The median age of presentation was 47.5 years. Five patients had a history of intravenous drug abuse, another 5 had underlying congenital heart disease, and 1 had both. Two patients (9.1%) had 2 microorganisms isolated. Staphylococcus aureus and Streptococcus viridans (3 cases, 13.6% each) were the most commonly implicated microorganism. Heart failure was the commonest complication, afflicting 11 patients (50.0%). Ten patients (45.5%) underwent surgery. Overall case fatality rate was 50.0%. Cardiac surgery was of statistical significance in predicting survival (P = 0.009).

CONCLUSION

Quadruple valve endocarditis is associated with a high mortality rate, and cardiac surgery may be protective.