title: Sources of HIV infection among men having sex with men and implications for prevention.
abstract: New HIV diagnoses among men having sex with men (MSM) have not decreased appreciably in most countries, even though care and prevention services have been scaled up substantially in the past 20 years. To maximize the impact of prevention strategies, it is crucial to quantify the sources of transmission at the population level. We used viral sequence and clinical patient data from one of Europe's nationwide cohort studies to estimate probable sources of transmission for 617 recently infected MSM. Seventy-one percent of transmissions were from undiagnosed men, 6% from men who had initiated antiretroviral therapy (ART), 1% from men with no contact to care for at least 18 months, and 43% from those in their first year of infection. The lack of substantial reductions in incidence among Dutch MSM is not a result of ineffective ART provision or inadequate retention in care. In counterfactual modeling scenarios, 19% of these past cases could have been averted with current annual testing coverage and immediate ART to those testing positive. Sixty-six percent of these cases could have been averted with available antiretrovirals (immediate ART provided to all MSM testing positive, and preexposure antiretroviral prophylaxis taken by half of all who test negative for HIV), but only if half of all men at risk of transmission had tested annually. With increasing sequence coverage, molecular epidemiological analyses can be a key tool to direct HIV prevention strategies to the predominant sources of infection, and help send HIV epidemics among MSM into a decisive decline.
authors.affiliation: Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W21PG, UK. oliver.ratmann@imperial.ac.uk.
authors.forename: Oliver
authors.initials: O
authors.lastname: Ratmann
authors.affiliation: Stichting HIV Monitoring, 1105 BD Amsterdam, the Netherlands.
authors.forename: Ard
authors.initials: A
authors.lastname: van Sighem
authors.affiliation: Stichting HIV Monitoring, 1105 BD Amsterdam, the Netherlands.
authors.forename: Daniela
authors.initials: D
authors.lastname: Bezemer
authors.affiliation: Department of Computer Science, University of Auckland, Auckland 1142, New Zealand.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Gavryushkina
authors.affiliation: Department of Medical Microbiology, Academic Medical Center, 1105 AZ Amsterdam, the Netherlands.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Jurriaans
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Wensing
authors.affiliation: Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W21PG, UK.
authors.forename: Frank
authors.initials: F
authors.lastname: de Wolf
authors.affiliation: Stichting HIV Monitoring, 1105 BD Amsterdam, the Netherlands. Department of Global Health, Academic Medical Center, 1105 BM Amsterdam, the Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Reiss
authors.affiliation: Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W21PG, UK.
authors.forename: Christophe
authors.initials: C
authors.lastname: Fraser
mesh_terms: D000328:Adult; D015658:HIV Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control* / Q000635:transmission; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D010802:Phylogeny