title: Sexual risk behaviour of men who have sex with men: emerging patterns and new challenges.
abstract: OBJECTIVE
  Antiretroviral treatment means that an increasing number of men who have sex with men (MSM) are living with HIV. The present review focuses on continuing transmission of HIV, risk factors for HIV infection in HIV-negative MSM, risk behaviour and risk reduction interventions among HIV-positive MSM, sexually transmitted infections, HIV and ageing and new and emerging populations of MSM communities.
  
  
  RESULTS
  Transmission of HIV infection continues in populations of MSM; transmission may be particularly high from main partners. Serosorting offers limited protection against HIV infection for HIV-negative MSM; negotiated safety and strategic positioning may be partially protective. For HIV-positive men, serosorting is a strategy to prevent HIV transmission, but has contributed to high rates of new non-HIV sexually transmitted infections. Sexual networks are important to the understanding of emerging sexually transmitted infections; ageing brings a new dimension to research on HIV.
  
  
  CONCLUSIONS
  Strategies other than exclusive condom use have emerged in communities of MSM to reduce the risk of HIV transmission, including serosorting and strategic positioning. 'Combination prevention' - using social structural, behavioural and biomedical approaches in tandem - could reduce the risk of HIV transmission, and may be particularly suited to HIV-positive MSM.
authors: Research Department of Infection and Population Health, University College London, UK. g.hart@ucl.ac.uk
authors: Graham J
authors: GJ
authors: Hart
authors: Jonathan
authors: J
authors: Elford
mesh_terms: D015658:HIV Infections / Q000517:prevention & control / Q000635:transmission*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D012309:Risk-Taking; D012725:Sexual Behavior