Background Empyema is a serious complication of pneumonia frequently caused by Streptococcus pneumoniae (SP). We assessed the impact of the 13-valent pneumococcal conjugate vaccine (13vPCV) on childhood pneumonia and empyema after inclusion in the Australian National Immunisation Program.
Methods For bacterial pneumonia and empyema hospitalisations, we ascertained incidence rates (IRs) using the National Hospital Morbidity Database International Statistical Classification of Disease discharge codes and relevant population denominators, and calculated incidence rate ratios (IRR) comparing the 13vPCV period (June 2012–May 2017) with the 7vPCV period (June 2007–May 2011). Blood and pleural fluid (PF) cultures and PF PCR of 401 children with empyema from 11 Australian hospitals during the 13vPCV period were compared with our previous study in the 7vPCV period.
Findings Across 7vPCV and 13vPCV periods, IRs per million children (95% CIs) were 1605 (1588 to 1621) and 1272 (1259 to 1285) for bacterial pneumonia, and 14.23 (12.67 to 15.79) and 17.89 (16.37 to 19.42) for empyema hospitalisations. IRRs were 0.79 (0.78 to 0.80) for bacterial pneumonia and 1.25 (1.09 to 1.44) for empyema. Of 161 empyema cases with SP serotypes, 147 (91.3%) were vaccine types. ST3 accounted for 76.4% of identified serotypes in the 13vPCV period, more than double than the 7vPCV period (p<0.001); ST19A decreased from 36.4% to 12.4%. No cases of ST1 empyema were identified in the 13vPCV period versus 14.5% in the 7vPCV period.
Interpretation 13vPCV resulted in a significant reduction in all-cause hospitalisations for bacterial pneumonia but empyema hospitalisations significantly increased, with emergence of pneumococcal ST3 as the dominant serotype in empyema.
Trial registration number Australian and New Zealand Clinical Trial Registry ACTRN 12614000354684.
- bacterial infection
- respiratory infection
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Twitter @MejbahBhuiyan, @sarathranganathan
Contributors RS, AJ and TS were responsible for the original conception and design of the study. RS, AJ, TS, SB, MUB, KM, HM, ACM, GBM, AM, TM, PM, SR, SS, CEW and AW were all equally responsible for the acquisition of data. RS, AJ, TS and NH performed the initial data analysed and drafted the initial manuscript. All authors contributed equally to the interpretation of the data, ongoing revision and final approval of the manuscript to be published.
Funding This study was funded by a research grant from the Australian National Health and Medical Research Council GNT1064841.
Disclaimer The NHMRC had no involvement in any aspect of this research, including study design, recruitment, data collection, data analysis and interpretation or writing up of results. The corresponding author had full access to all data in the study and had final responsibility for the decision to submit for publication.
Competing interests HM is an investigator on sponsored vaccine trials. Her institution receives funding from Pfizer and GSK for investigator-led research. She does not receive any personal payments from Industry.
Patient consent for publication Not required.
Ethics approval The targeted surveillance study was approved by the Human Research Ethics Committee at each sentinel site. National hospitalisation data were obtained from a publicly available deidentified administrative dataset and did not require ethics approval (www.aihw.gov.au).
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available upon reasonable request. Deidentified participant source data available upon reasonable request.
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