title: Syphilis treatment response among HIV-discordant couples in Zambia and Rwanda.
abstract: BACKGROUND
  Syphilis continues to be a common sexually transmitted infection, despite the availability of inexpensive and effective treatment. Infection in human immunodeficiency virus (HIV)-discordant couples is important because syphilis increases the risk of HIV acquisition. Current US treatment guidelines recommend 1 dose of benzathine penicillin for early syphilis, irrespective of HIV status, but data from coinfected patients are limited.
  
  
  METHODS
  Retrospective analysis of 1321 individuals in 2 African HIV-discordant couple cohorts was performed. Cox proportional hazards analysis and multivariable modeling were used to assess predictors of serologic response to treatment at 180 days and 400 days. Modeling was performed for all episodes of positive rapid plasma reagin (RPR) test results and on a subset with higher RPR titers (≥1:4).
  
  
  RESULTS
  A total of 1810 episodes of syphilis among 1321 individuals were treated with penicillin between 2002 and 2008. Although a positive RPR was more common in the HIV-infected partners, HIV infection did not impact the likelihood of serologic response to therapy (odds ratio [OR], 1.001; P = .995). By 400 days, 67% had responded to therapy, 27% were serofast, and 6.5% had documented reinfection. Prevalent infections were more likely to remain serofast than incident infections (33% vs 20% at 400 days).
  
  
  CONCLUSIONS
  In 2 HIV-serodiscordant couple cohorts in Africa, incident syphilis had a very good likelihood of response to penicillin therapy, irrespective of HIV infection. This supports current Centers for Disease Control and Prevention treatment guidelines. A high proportion of prevalent RPR-positive infections remain serofast despite treatment.
authors.affiliation: Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, NH 03756, USA. jodie.a.dionne-odom@hitchcock.org
authors.forename: Jodie
authors.initials: J
authors.lastname: Dionne-Odom
authors.forename: Etienne
authors.initials: E
authors.lastname: Karita
authors.forename: William
authors.initials: W
authors.lastname: Kilembe
authors.forename: Faith
authors.initials: F
authors.lastname: Henderson
authors.forename: Bellington
authors.initials: B
authors.lastname: Vwalika
authors.forename: Roger
authors.initials: R
authors.lastname: Bayingana
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Li
authors.forename: Joseph
authors.initials: J
authors.lastname: Mulenga
authors.forename: Elwyn
authors.initials: E
authors.lastname: Chomba
authors.forename: Carlos
authors.initials: C
authors.lastname: Del Rio
authors.forename: Naw Htee
authors.initials: NH
authors.lastname: Khu
authors.forename: Amanda
authors.initials: A
authors.lastname: Tichacek
authors.forename: Susan
authors.initials: S
authors.lastname: Allen
mesh_terms: D000293:Adolescent; D000328:Adult; D000993:Antitreponemal Agents / Q000627:therapeutic use; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000382:microbiology*; D018023:HIV Seronegativity; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010406:Penicillins / Q000627:therapeutic use; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012432:Rwanda / Q000453:epidemiology; D018454:Spouses / Q000706:statistics & numerical data*; D013587:Syphilis / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology*; D016896:Treatment Outcome; D015024:Zambia / Q000453:epidemiology
chemical_list: D000993:Antitreponemal Agents; D010406:Penicillins
keywords: HIV/AIDS; Rwanda; Zambia; discordant couples; syphilis