title: Reduction of concentration of HIV-1 in semen after treatment of urethritis: implications for prevention of sexual transmission of HIV-1. AIDSCAP Malawi Research Group.
abstract: BACKGROUND
  Transmission of HIV-1 is predominantly by heterosexual contact in sub-Saharan Africa, where sexually transmitted diseases (STDs) are also common. Epidemiological studies suggest that STDs facilitate transmission of HIV-1, but the biological mechanism remains unclear. We investigated the hypothesis that STDs increase the likelihood of transmission of HIV-1 through increased concentration of the virus in semen.
  
  
  METHODS
  HIV-1 RNA concentrations were measured in seminal and blood plasma from 135 HIV-1-seropositive men in Malawi; 86 had urethritis and 49 controls did not have urethritis. Men with urethritis received antibiotic treatment according to the guidelines of the Malawian STD Advisory Committee. Samples were analysed at baseline and at week 1 and week 2 after antibiotic therapy in urethritis patients, and at baseline and week 2 in the control group.
  
  
  RESULTS
  HIV-1-seropositive men with urethritis had HIV-1 RNA concentrations in seminal plasma eight times higher than those in seropositive men without urethritis (12.4 vs 1.51 x 10(4) copies/mL, p = 0.035), despite similar CD4 counts and concentrations of blood plasma viral RNA. Gonorrhoea was associated with the greatest concentration of HIV-1 in semen (15.8 x 10(4) copies/mL). After the urethritis patients received antimicrobial therapy directed against STDs, the concentration of HIV-1 RNA in semen decreased significantly (from 12.4 x 10(4) copies/mL to 8.91 x 10(4) copies/mL at 1 week [p = 0.03] and 4.12 x 10(4) copies/mL at 2 weeks [p = 0.0001]). Blood plasma viral RNA concentrations did not change. There was no significant change in seminal plasma HIV-1 RNA concentrations during the 2-week period in the control group (p = 0.421).
  
  
  CONCLUSIONS
  These results suggest that urethritis increases the infectiousness of men with HIV-1 infection. HIV-1-control programmes, which include detection and treatment of STDs in patients already infected with HIV-1, may help to curb the epidemic. Targeting of gonococcal urethritis may be a particularly effective strategy.
authors.affiliation: Department of Medicine, University of North Carolina, Chapel Hill 27599-7030, USA. mscohen@med.unc.edu
authors.forename: M S
authors.initials: MS
authors.lastname: Cohen
authors.forename: I F
authors.initials: IF
authors.lastname: Hoffman
authors.forename: R A
authors.initials: RA
authors.lastname: Royce
authors.forename: P
authors.initials: P
authors.lastname: Kazembe
authors.forename: J R
authors.initials: JR
authors.lastname: Dyer
authors.forename: C C
authors.initials: CC
authors.lastname: Daly
authors.forename: D
authors.initials: D
authors.lastname: Zimba
authors.forename: P L
authors.initials: PL
authors.lastname: Vernazza
authors.forename: M
authors.initials: M
authors.lastname: Maida
authors.forename: S A
authors.initials: SA
authors.lastname: Fiscus
authors.forename: J J
authors.initials: JJ
authors.lastname: Eron
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000517:prevention & control* / Q000635:transmission / Q000821:virology; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D006679:HIV Seropositivity / Q000821:virology; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D008295:Malawi; D008297:Male; D012367:RNA, Viral / Q000032:analysis; D012661:Semen / Q000821:virology*; D012749:Sexually Transmitted Diseases / Q000517:prevention & control* / Q000635:transmission; D014526:Urethritis / Q000188:drug therapy* / Q000821:virology
chemical_list: D000900:Anti-Bacterial Agents; D012367:RNA, Viral