title: Sex, drugs (methamphetamines), and the Internet: increasing syphilis among men who have sex with men in California, 2004-2008.
abstract: OBJECTIVE
  We examined primary and secondary syphilis cases among men who have sex with men (MSM) in California, and the association of methamphetamine use and Internet use to meet sex partners (Internet use) with number of sex partners.
  
  
  METHODS
  We analyzed California surveillance data for MSM who were diagnosed with syphilis between 2004 and 2008, to assess differences in the mean number of sex partners by methamphetamine use and mutually exclusive groups of patients reporting Internet use (Internet users).
  
  
  RESULTS
  Large proportions of patients reported methamphetamine use (19.2%) and Internet use (36.4%). From 2006 through 2008, Adam4Adam was the most frequently reported Web site statewide, despite temporal and regional differences in Web site usage. Methamphetamine users reported more sex partners (mean = 11.7) than nonmethamphetamine users (mean = 5.6; P < .001). Internet users reported more sex partners (mean = 9.8) than non-Internet users (mean = 5.0; P < .001). Multivariable analysis of variance confirmed an independent association of methamphetamine and Internet use with increased numbers of sex partners.
  
  
  CONCLUSIONS
  Higher numbers of partners among MSM syphilis patients were associated with methamphetamine and Internet use. Collaboration between currently stand-alone interventions targeting methamphetamine users and Internet users may offer potential advances in sexually transmitted disease control efforts.
authors.affiliation: California Department of Public Health, STD Control Branch, 850 Marina Bay Parkway, Bldg P, 2nd Floor, Richmond, CA 94804, USA. rilene.ng@cdph.ca.gov
authors.forename: Rilene A
authors.initials: RA
authors.lastname: Chew Ng
authors.forename: Michael C
authors.initials: MC
authors.lastname: Samuel
authors.forename: Terrence
authors.initials: T
authors.lastname: Lo
authors.forename: Kyle T
authors.initials: KT
authors.lastname: Bernstein
authors.forename: Getahun
authors.initials: G
authors.lastname: Aynalem
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Klausner
authors.forename: Gail
authors.initials: G
authors.lastname: Bolan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001727:Bisexuality; D002140:California / Q000453:epidemiology; D018451:Homosexuality, Male; D006801:Humans; D020407:Internet; D008297:Male; D008694:Methamphetamine; D008875:Middle Aged; D012309:Risk-Taking; D012725:Sexual Behavior; D012747:Sexual Partners; D012749:Sexually Transmitted Diseases / Q000453:epidemiology*; D019966:Substance-Related Disorders / Q000453:epidemiology*; D013587:Syphilis / Q000453:epidemiology*
chemical_list: D008694:Methamphetamine