title: Investigation of a Chlamydia pneumoniae outbreak in a Federal correctional facility in Texas.
abstract: BACKGROUND
  Chlamydia pneumoniae illness is poorly characterized, particularly as a sole causative pathogen. We investigated a C. pneumoniae outbreak at a federal correctional facility.
  
  
  METHODS
  We identified inmates with acute respiratory illness (ARI) from 1 November 2009 to 24 February 2010 through clinic self-referral and active case finding. We tested oropharyngeal and/or nasopharyngeal swabs for C. pneumoniae by real-time polymerase chain reaction (qPCR) and serum samples by microimmunofluorescence. Cases were inmates with ARI and radiologically confirmed pneumonia, positive qPCR, or serological evidence of recent infection. Swabs from 7 acutely ill inmates were tested for 18 respiratory pathogens using qPCR TaqMan Array Cards (TACs). Follow-up swabs from case patients were collected for up to 8 weeks.
  
  
  RESULTS
  Among 33 self-referred and 226 randomly selected inmates, 52 (20.1%) met the case definition; pneumonia was confirmed in 4 by radiology only, in 9 by qPCR only, in 17 by serology only, and in 22 by both qPCR and serology. The prison attack rate was 10.4% (95% confidence interval, 7.0%-13.8%). White inmates and residents of housing unit Y were at highest risk. TAC testing detected C. pneumoniae in 4 (57%) inmates; no other causative pathogens were identified. Among 40 inmates followed prospectively, C. pneumoniae was detected for up to 8 weeks. Thirteen (52%) of 25 inmates treated with azithromycin continued to be qPCR positive >2 weeks after treatment.
  
  
  CONCLUSIONS
  Chlamydia pneumoniae was the causative pathogen of this outbreak. Higher risk among certain groups suggests that social interaction contributed to transmission. Persistence of C. pneumoniae in the oropharynx creates challenges for outbreak control measures.
authors.affiliation: Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. lconklin@cdc.gov
authors.forename: Laura
authors.initials: L
authors.lastname: Conklin
authors.forename: Jennifer
authors.initials: J
authors.lastname: Adjemian
authors.forename: Jennifer
authors.initials: J
authors.lastname: Loo
authors.forename: Sema
authors.initials: S
authors.lastname: Mandal
authors.forename: Carol
authors.initials: C
authors.lastname: Davis
authors.forename: Sharyn
authors.initials: S
authors.lastname: Parks
authors.forename: Tina
authors.initials: T
authors.lastname: Parsons
authors.forename: Brian
authors.initials: B
authors.lastname: McDonough
authors.forename: Jorge
authors.initials: J
authors.lastname: Partida
authors.forename: Kathleen
authors.initials: K
authors.lastname: Thurman
authors.forename: Maureen H
authors.initials: MH
authors.lastname: Diaz
authors.forename: Alvaro
authors.initials: A
authors.lastname: Benitez
authors.forename: Tracy
authors.initials: T
authors.lastname: Pondo
authors.forename: Cynthia G
authors.initials: CG
authors.lastname: Whitney
authors.forename: Jonas M
authors.initials: JM
authors.lastname: Winchell
authors.forename: Newton
authors.initials: N
authors.lastname: Kendig
authors.forename: Chris
authors.initials: C
authors.lastname: Van Beneden
mesh_terms: D000328:Adult; D000368:Aged; D023521:Chlamydophila Infections / Q000453:epidemiology* / Q000382:microbiology; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification*; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000382:microbiology; D009960:Oropharynx / Q000382:microbiology; D018410:Pneumonia, Bacterial / Q000453:epidemiology* / Q000382:microbiology; D011330:Prisons; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology; D055815:Young Adult
keywords: Chlamydia pneumoniae; Chlamydophila; atypical pneumonia; community-acquired pneumonia; prison