title: Asplenic patients and invasive pneumococcal disease-how bad is it these days?
abstract: OBJECTIVE
  Most are aware of pneumococcal infection as a complication of splenectomy and the increased risk of severe invasive pneumococcal disease (IPD) in asplenic patients. However little is known of the current status of this entity in a population with an active pneumococcal conjugate vaccine program for children.
  
  
  METHODS
  All IPD cases reported from 2000 to 2014 in Northern Alberta, Canada were collected prospectively. Socio-demographic variables, clinical characteristics, and IPD-related outcomes were compared between patients with and without a spleen using the Student t-test, Chi-square test, or Fisher's exact test, as appropriate.
  
  
  RESULTS
  Thirty-seven of 2435 patients with IPD (1.5%) were asplenic. Asplenic patients were significantly more likely to require mechanical ventilation or admission to the intensive care unit and had more complications (e.g., acute kidney injury). However, in-hospital mortality rates were similar in those with and without a spleen (19% vs. 16%, p=0.58). Pneumococcal serotype 22B was 33-fold higher in asplenic patients compared to those with a spleen.
  
  
  CONCLUSIONS
  In patients with IPD, those who are asplenic have a more severe infection than those with a spleen; however, the mortality rate is not significantly different. The reason for the predominance of serotype 22B requires further investigation and if replicated may warrant attention to current vaccination strategies.
authors: Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
authors: Thomas J
authors: TJ
authors: Marrie
authors: Division of Diagnostic and Applied Microbiology, Department of Laboratory Medicine and Pathology, University of Alberta, and The Provincial Laboratory for Public Health, Edmonton, Alberta, Canada.
authors: Gregory J
authors: GJ
authors: Tyrrell
authors: Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
authors: Sumit R
authors: SR
authors: Majumdar
authors: School of Public Health, University of Alberta, 2-040 Li Ka Shing HRIF, Edmonton, Alberta, T6G 2E1, Canada. Electronic address: deurich@ualberta.ca.
authors: Dean T
authors: DT
authors: Eurich
mesh_terms: D000416:Alberta; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000209:etiology*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology; D012703:Serotyping; D013154:Spleen / Q000502:physiology / Q000601:surgery; D013156:Splenectomy / Q000009:adverse effects*; D013296:Streptococcus pneumoniae / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage
chemical_list: D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Invasive pneumococcal disease; Spleen; Splenectomy; Streptococcus pneumoniae