PAEDIATRIC INVASIVE PNEUMOCOCCAL DISEASE- 5 YEAR RETROSPECTIVE ANALYSIS OF SEROTYPES AND ANTIMICROBIAL SUSCEPTIBILITIES AT A SCOTTISH TERTIARY REFERRAL HOSPITAL.

A. Balfour, K. Harvey-Wood, A. Deshpande, E. McCormick.
Royal Hospital for Children, Microbiology Dept, Glasgow, United Kingdom.

Background
Invasive pneumococcal disease (IPD) remains an important cause of morbidity and mortality worldwide. In the UK the 13-valent pneumococcal conjugate vaccine (PCV 13) was introduced in 2010 as part of the NHS childhood vaccination programme. Despite vaccination invasive disease still occurs and early detection with prompt management including appropriate antibiotics is required.

Methods
Retrospective analysis of laboratory electronic records for 5 years, 01/01/13-31/12/17. Data retrieved from Clinical Portal and Telepath systems included age, sex, date of specimen, specimen type, and serotype of invasive Streptococcus pneumoniae. Isolates sent to the Scottish Haemophilus, Legionella, Meningococcus and Pneumococcus Reference Laboratory (SHLMPRL) analysed for serotype, MLST and antimicrobial sensitivities; data then cross referred with patient data.

Results
A total of 40 IPD episodes were recorded: 33 (82.5%) bacteraemias, 6 (15%) cerebrospinal fluids (CSFs), one (2.5%) pleural fluid. There was no temporal pattern detected nor serotype commonality. Children aged ≤5 accounted for 27 (67.5%) cases, with overall sex ratio 21 males: 19 females. Eleven (27.5%) IPD episodes were caused by serotypes contained in 13-valent PCV whereas 33 (82.5%) were caused by serotypes contained in 23-valent PPV. All isolates had penicillin MIC<2 mg/L (within EUCAST non-meningitis values) and two had MIC 0.25mg/L, outwith EUCAST values for meningitis. Both were bacteraemias caused by serotypes not found in any pneumococcal vaccines

Conclusions
This review confirmed that the burden of IPD occurs in those aged ≤5 and predominantly by serotypes not contained in PCV 13. Reasons for IPD due to serotypes present in PCV 13 include failure to receive vaccine, or failure to mount adequate immune response. Ongoing surveillance of serotypes and antimicrobial susceptibilities is required both locally and nationally to ensure appropriate vaccine serotype coverage and vigilance concerning emerging antimicrobial resistance.

PAEDIATRIC INVASIVE PNEUMOCOCCAL DISEASE- 5 YEAR RETROSPECTIVE ANALYSIS OF SEROTYPES AND ANTIMICROBIAL SUSCEPTIBILITIES AT A SCOTTISH TERTIARY REFERRAL HOSPITAL