Colonisation of Irish patients with chronic obstructive pulmonary disease by <i>Streptococcus pneumoniae</i> and analysis of the pneumococcal vaccine coverage: a non-interventional, observational, prospective cohort study.

Abstract

To characterise the pattern of colonisation and serotypes of <i>Streptococcus pneumoniae</i> among patients with chronic obstructive pulmonary disease (COPD) who currently receive the 23-valent pneumococcal polysaccharide vaccine (PPV-23) according to vaccination status, use of antibiotics and steroids. To investigate the prevalence of PPV-23 and 13-valent pneumococcal conjugate vaccine (PCV-13) serotypes within the study cohort. A non-interventional, observational, prospective cohort study with a 12 -month follow-up period inclusive of quarterly study visits. Beaumont Hospital and The Royal College of Surgeons in Ireland Clinical Research Centre, Dublin, Ireland. Patients with an established diagnosis of COPD attending a tertiary medical centre. Colonisation rate of <i>S. pneumoniae</i> in patients with COPD and characterisation of serotypes of <i>S. pneumoniae</i> with correlation to currently available pneumococcal vaccines. Sputum and oropharyngeal swab samples were collected for the isolation of <i>S. pneumoniae</i>. Seasonality of colonisation of <i>S. pneumoniae</i> and its relationship with the incidence of exacerbations of COPD. <i>S. pneumoniae</i> was detected in 16 of 417 samples, a colonisation incident rate of 3.8% and in 11 of 133 (8%) patients at least once during the study. The majority of <i>S. pneumoniae</i> isolates were identified in spring and were non-vaccine serotypes for either the PPV-23 or PCV-13 (63%). The colonisation incident rate of <i>S. pneumoniae</i> fluctuated over the four seasons with a peak of 6.6% in spring and the lowest rate of 2.2% occurring during winter. Antibiotic use was highest during periods of low colonisation. There is seasonal variation in <i>S. pneumoniae</i> colonisation among patients with COPD which may reflect antibiotic use in autumn and winter. The predominance of non-vaccine types suggests that PCV-13 may have limited impact among patients with COPD in Ireland who currently receive PPV-23. NCT02535546; post-results.