title: Prevalence and incidence of pharyngeal gonorrhea in a longitudinal sample of men who have sex with men: the EXPLORE study.
abstract: BACKGROUND
  The prevalence of gonorrhea of the pharynx among select samples of men who have sex with men (MSM) ranges from 9% to 15%. To our knowledge, there have been no longitudinal studies in a prospective MSM cohort to estimate pharyngeal gonorrhea incidence or predictors of infection. We examined the prevalence, incidence, and sociodemographic and behavioral predictors of pharyngeal gonorrhea in a cohort of sexually active, human immunodeficiency virus-negative MSM.
  
  
  METHODS
  We conducted a prospective study of pharyngeal gonorrhea among MSM who were enrolled in a behavioral intervention study to prevent human immunodeficiency virus infection (Project EXPLORE). Participants were enrolled in this ancillary study from March 2001 through July 2003. At baseline and every 6 months thereafter until 31 July 2003, participants were tested for pharyngeal gonorrhea and were administered a questionnaire regarding their oral sex practices. Rectal and urethral gonorrhea testing were also performed.
  
  
  RESULTS
  Prevalence of pharyngeal gonorrhea was 5.5% (136 cases diagnosed from 2475 tests). The incidence rate was 11.2 cases per 100 person-years. Pharyngeal gonorrhea was positively associated with younger age and the number of insertive oral sex partners in the past 3 months. Ejaculation did not increase the risk of pharyngeal gonorrhea. Gonorrhea of the pharynx was asymptomatic in 92% of cases.
  
  
  CONCLUSIONS
  The pharynx is a common, asymptomatic reservoir for gonorrhea in sexually active MSM.
authors.affiliation: Department of Community and Family Medicine, University of California San Francisco, USA.
authors.forename: Sheldon R
authors.initials: SR
authors.lastname: Morris
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Klausner
authors.forename: Susan P
authors.initials: SP
authors.lastname: Buchbinder
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Wheeler
authors.forename: Beryl
authors.initials: B
authors.lastname: Koblin
authors.forename: Thomas
authors.initials: T
authors.lastname: Coates
authors.forename: Margaret
authors.initials: M
authors.lastname: Chesney
authors.forename: Grant N
authors.initials: GN
authors.lastname: Colfax
mesh_terms: D006069:Gonorrhea / Q000453:epidemiology*; D018451:Homosexuality, Male; D006801:Humans; D015994:Incidence; D008297:Male; D009344:Neisseria gonorrhoeae; D010608:Pharyngeal Diseases / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D011446:Prospective Studies; D012723:Sex; D012725:Sexual Behavior; D012749:Sexually Transmitted Diseases / Q000150:complications / Q000453:epidemiology