Emerging Infectious Diseases (May 2012)

Epidemic of Invasive Pneumococcal Disease, Western Canada, 2005–2009

  • Gregory J. Tyrrell,
  • Marguerite Lovgren,
  • Quazi Ibrahim,
  • Sipi Garg,
  • Linda Chui,
  • Tyler J. Boone,
  • Carol Mangan,
  • David M. Patrick,
  • Linda Hoang,
  • Greg B. Horsman,
  • Paul Van Caeseele,
  • Thomas J. Marrie

DOI
https://doi.org/10.3201/eid1805.110235
Journal volume & issue
Vol. 18, no. 5
pp. 733 – 740

Abstract

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In Canada before 2005, large outbreaks of pneumococcal disease, including invasive pneumococcal disease caused by serotype 5, were rare. Since then, an epidemic of serotype 5 invasive pneumococcal disease was reported: 52 cases during 2005, 393 during 2006, 457 during 2007, 104 during 2008, and 42 during in 2009. Of these 1,048 cases, 1,043 (99.5%) occurred in the western provinces of Canada. Median patient age was 41 years, and most (659 [59.3%]) patients were male. Most frequently representing serotype 5 cases (compared with a subset of persons with non–serotype 5 cases) were persons who were of First Nations heritage or homeless. Restriction fragment-length polymorphism typing indicated that the epidemic was caused by a single clone, which multilocus sequence typing identified as sequence type 289. Large pneumococcal epidemics might go unrecognized without surveillance programs to document fluctuations in serotype prevalence.

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