title: Clinical features of adults with seven-valent-conjugated-vaccine-serotype pneumococcal pneumonia.
abstract: BACKGROUND
  Despite the reduction in adult invasive pneumococcal disease through 'herd protection' consequent to the introduction of childhood pneumococcal conjugate vaccination (PCV), a significant proportion of adults continue to develop pneumococcal pneumonia caused by one of the seven serotypes included in the seven-valent conjugated pneumococcal vaccine (PCV7). The clinical features and outcomes of these adults have not been previously reported.
  
  
  METHODS
  Adults recruited over a three year period to a large prospective cohort study of community acquired pneumonia (CAP) were investigated for pneumococcal serotypes using a validated multiplex immunoassay (Bio-plex). The baseline characteristics and outcomes of adults with PCV7-serotype CAP in comparison to those with non-PCV7-serotype CAP were established.
  
  
  RESULTS
  Pneumococcal aetiology was identified in 415 of 1166 (35.6%) individuals, and a serotype determined in 287 (69.2%). Following exclusion of three individuals with both a PCV7 and non-PCV7 serotype, 77 of the remaining 284 (27.1%) adults had CAP due to PCV7 serotypes. Adults with PCV7-serotype CAP were older (median years (inter-quartile range) 73.3 (60.8-84.4) versus 65.0 (46.1-78.0); p=0.001) and were more likely to have a World Health Organisation performance status ≥1 (odds ratio (OR) 2.05, 95% confidence interval (CI) 1.21-3.50).The presence of stroke (adjusted OR 2.84, 95% CI 1.36-5.95) and dementia (adjusted OR 3.55, 95% CI 1.26-9.94) as underlying co-morbid illnesses were independently associated with PCV7-serotype CAP; 30-day mortality was significantly greater in adults with PCV7-serotype CAP (adjusted OR 4.38, 95% CI 1.85-10.34).
  
  
  CONCLUSIONS
  A significant proportion of adults continue to develop PCV7-serotype CAP in the era of childhood pneumococcal conjugate vaccination. These adults are more likely to have stroke and dementia as underlying co-morbid illnesses, and have a higher 30-day mortality. A combination of pneumococcal transmission factors, host factors and pneumococcal serotype specific characteristics are likely to explain these findings.
authors: Department of Respiratory Medicine, City Hospital Campus, Nottingham University Hospitals NHS Trust, Hucknall Road, Nottingham NG5 1PB, UK. Electronic address: chamira@doctors.org.uk.
authors: Chamira
authors: C
authors: Rodrigo
authors: Department of Respiratory Medicine, City Hospital Campus, Nottingham University Hospitals NHS Trust, Hucknall Road, Nottingham NG5 1PB, UK.
authors: Thomas
authors: T
authors: Bewick
authors: Respiratory and Systemic Infection Laboratory, Public Health England, Microbiology Services Division, Colindale Avenue, London NW9 5EQ, UK.
authors: Carmen
authors: C
authors: Sheppard
authors: Department of Respiratory Medicine, City Hospital Campus, Nottingham University Hospitals NHS Trust, Hucknall Road, Nottingham NG5 1PB, UK.
authors: Sonia
authors: S
authors: Greenwood
authors: Disease Dynamics Unit, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.
authors: Caroline
authors: C
authors: Trotter
authors: Respiratory and Systemic Infection Laboratory, Public Health England, Microbiology Services Division, Colindale Avenue, London NW9 5EQ, UK.
authors: Mary
authors: M
authors: Slack
authors: Respiratory and Systemic Infection Laboratory, Public Health England, Microbiology Services Division, Colindale Avenue, London NW9 5EQ, UK.
authors: Robert
authors: R
authors: George
authors: Department of Respiratory Medicine, City Hospital Campus, Nottingham University Hospitals NHS Trust, Hucknall Road, Nottingham NG5 1PB, UK.
authors: Wei Shen
authors: WS
authors: Lim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000517:prevention & control; D003704:Dementia / Q000150:complications; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D008297:Male; D008875:Middle Aged; D022242:Pneumococcal Vaccines / Q000008:administration & dosage; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology* / Q000517:prevention & control; D011446:Prospective Studies; D012307:Risk Factors; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification*; D020521:Stroke / Q000150:complications
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines
keywords: Pneumococcal; Pneumonia; Serotype; Vaccine