title: Ureaplasma urealyticum is associated with nongonococcal urethritis among men with fewer lifetime sexual partners: a case-control study.
abstract: BACKGROUND
  Ureaplasmas have been inconsistently associated with nongonococcal urethritis (NGU). We evaluated the association of the newly differentiated species Ureaplasma urealyticum (UU) and Ureaplasma parvum (UP) with NGU using 2 separate control groups.
  
  
  METHODS
  Case patients were men who attended a sexually transmitted disease (STD) clinic in Seattle, Washington, during the period 2007-2009 with NGU (defined as visible urethral discharge and/or ≥5 polymorphonuclear neutrophils per high-powered field; n = 329). Control subjects were STD clinic attendees (n = 191) and emergency department (ED) attendees (n = 193) without NGU. Polymerase chain reaction assays detected UU and UP in ureaplasma culture-positive urine. Multivariable logistic regression was used to assess the associations of UU and UP with NGU.
  
  
  RESULTS
  UU was only marginally associated with NGU in aggregate multivariable analyses, irrespective of control group (adjusted odds ratio [aOR](STD-control), 1.6 [95% confidence interval {CI}, 0.9-2.8]; aOR(ED-control), 1.7 [95% CI, 0.97-3.0]). This association was significantly stronger when analyses were restricted to men with fewer lifetime sex partners (<10 vaginal partners: aOR(STD-control), 2.9 [95% CI, 1.2-6.7]; aOR(ED-control), 3.2 [95% CI, 1.3-7.6]; <5 vaginal partners: aOR(STD-control), 6.2 [95% CI, 1.8-21.0]; aOR(ED-control), 5.2 [95% CI, 1.3-20.2]). UP was not positively associated with NGU overall or among subgroups.
  
  
  CONCLUSIONS
  The absence of an association of UU with NGU among men with more lifetime sex partners suggests that adaptive immunity may attenuate the clinical manifestation of UU infection. Similar relationships were not observed with UP, which suggests that it is not a urethral pathogen.
authors.affiliation: Center for AIDS and STD, University of Washington, Seattle, Washington, USA. cwetmore@u.washington.edu
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Wetmore
authors.forename: Lisa E
authors.initials: LE
authors.lastname: Manhart
authors.forename: M Sylvan
authors.initials: MS
authors.lastname: Lowens
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Golden
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Jensen
authors.forename: Sabina G
authors.initials: SG
authors.lastname: Astete
authors.forename: William L H
authors.initials: WL
authors.lastname: Whittington
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Totten
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012747:Sexual Partners; D014509:Ureaplasma / Q000302:isolation & purification*; D016869:Ureaplasma Infections / Q000453:epidemiology* / Q000382:microbiology; D016990:Ureaplasma urealyticum / Q000302:isolation & purification*; D014526:Urethritis / Q000453:epidemiology* / Q000382:microbiology; D014861:Washington / Q000453:epidemiology; D055815:Young Adult