title: Use of the serologic testing algorithm for recent HIV seroconversion (STARHS) to identify recently acquired HIV infections in men with early syphilis in Los Angeles County.
abstract: BACKGROUND
  Syphilis outbreaks among men who have sex with men (MSM) in the United States, many of whom are HIV infected, have prompted increased concern for HIV transmission.
  
  
  METHODS
  To identify whether men are acquiring HIV concomitantly or within the critical period of syphilis infection, banked Treponema pallidum particle agglutination-positive serum specimens from men with early syphilis infection were screened for HIV-1 antibody. Samples that were positive for HIV antibody were then tested with a less sensitive (LS) HIV-1 antibody enzyme immunoassay (serologic testing algorithm for recent HIV seroconversion [STARHS]) to identify HIV infections that occurred on average within the previous 6 months.
  
  
  RESULTS
  Of the 212 specimens banked from men with early syphilis, 74 (35%) were HIV-positive. Of these, 15 tested non-reactive by the LS assay. Twelve of these 15 were considered to be recent infections by the LS assay and testing history. Eleven (92%) of the recent infections were among MSM. One man had primary syphilis, 6 (50%) had secondary syphilis, and 5 (42%) had early latent syphilis. Eight men (67%) reported sex with anonymous partners, and 3 (25%) reported consistent condom use. The estimated HIV incidence was 17% per year (95% confidence interval [CI]: 12%-22%) among all men with early syphilis, and it was 26% per year (95% CI: 91%-33%) among MSM.
  
  
  CONCLUSIONS
  Syphilis epidemics in MSM may be contributing to HIV incidence in this population. The STARHS can be applied as a surveillance tool to assess HIV incidence in various at-risk populations, but further studies are necessary for validation.
authors.affiliation: Division of STD Prevention, National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA. metaylor@dhs.co.la.ca.us
authors.forename: Melanie M
authors.initials: MM
authors.lastname: Taylor
authors.forename: Kellie
authors.initials: K
authors.lastname: Hawkins
authors.forename: Anthony
authors.initials: A
authors.lastname: Gonzalez
authors.forename: Kate
authors.initials: K
authors.lastname: Buchacz
authors.forename: Getahun
authors.initials: G
authors.lastname: Aynalem
authors.forename: Lisa V
authors.initials: LV
authors.lastname: Smith
authors.forename: Jeff
authors.initials: J
authors.lastname: Klausner
authors.forename: Scott
authors.initials: S
authors.lastname: Holmberg
authors.forename: Peter R
authors.initials: PR
authors.lastname: Kerndt
mesh_terms: D000328:Adult; D000465:Algorithms; D015658:HIV Infections / Q000150:complications* / Q000175:diagnosis; D006679:HIV Seropositivity / Q000175:diagnosis*; D006801:Humans; D015141:Los Angeles; D008297:Male; D008875:Middle Aged; D012309:Risk-Taking; D012698:Serologic Tests / Q000379:methods*; D012725:Sexual Behavior; D013587:Syphilis / Q000150:complications* / Q000175:diagnosis