title: Large community outbreak of Streptococcus pneumoniae serotype 5 invasive infection in an impoverished, urban population.
abstract: BACKGROUND
  Streptococcus pneumoniae is a common cause of sporadic invasive infections, but outbreaks of invasive pneumococcal disease are infrequent. In August 2006, a sudden increase in the number of patients presenting with invasive pneumococcal disease was noted at St. Paul's Hospital (Vancouver, Canada). Most patients with severe disease resided in an area referred to as the Downtown Eastside, a neighborhood known for its high rates of poverty and illicit drug use.
  
  
  METHODS
  Prospective, laboratory-based surveillance for invasive pneumococcal disease was initiated, including on-site serotyping of S. pneumoniae isolates. A vaccination campaign using 23-valent polysaccharide pneumococcal vaccine was launched in the Downtown Eastside. Multiple logistic regression was used to examine the association of sociodemographic variables and medical risk factors with S. pneumoniae serotype status.
  
  
  RESULTS
  A single S. pneumoniae serotype (serotype 5) was responsible for 78% of invasive pneumococcal disease cases (137 of 175 cases) during the outbreak period of August 2006-July 2007. The outbreak strain, although fully susceptible to penicillin, caused significant morbidity and placed considerable strain on the acute care system within the Vancouver Coastal Health region. Crack cocaine use was found to be the main independent risk factor associated with invasive pneumococcal disease due to S. pneumoniae serotype 5 (odds ratio, 12.4; 95% confidence interval, 2.22-69.5).
  
  
  CONCLUSIONS
  A targeted vaccination campaign using polysaccharide pneumococcal vaccine appeared to help control this outbreak. In urban centers with high rates of illicit drug use, vaccination strategies for preventing invasive pneumococcal disease may need to be refined to include individuals who use crack cocaine.
authors.affiliation: Department of Pathology, Laboratory Medicine, St Paul's Hospital, Providence Health Care, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. mromney@providencehealth.bc.ca
authors.forename: Marc G
authors.initials: MG
authors.lastname: Romney
authors.forename: Mark W
authors.initials: MW
authors.lastname: Hull
authors.forename: Réka
authors.initials: R
authors.lastname: Gustafson
authors.forename: Jat
authors.initials: J
authors.lastname: Sandhu
authors.forename: Sylvie
authors.initials: S
authors.lastname: Champagne
authors.forename: Titus
authors.initials: T
authors.lastname: Wong
authors.forename: Anouf
authors.initials: A
authors.lastname: Nematallah
authors.forename: Sara
authors.initials: S
authors.lastname: Forsting
authors.forename: Patricia
authors.initials: P
authors.lastname: Daly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001955:British Columbia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016578:Crack Cocaine; D004196:Disease Outbreaks / Q000517:prevention & control; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000517:prevention & control; D011204:Poverty Areas; D012703:Serotyping; D014505:Urban Population; D055815:Young Adult
chemical_list: D016578:Crack Cocaine