Ongoing syphilis epidemic among HIV-infected men who have sex with men in Austria
S. Gogl1, M. Kitchen2, M. Sarcletti2, M. Geit3, A. Rieger4, B. Haas5, N. Taylor6, M. Kanatschnig7, M. Joechl1, R. Zangerle2, Austrian HIV Cohort Study Group
1Austrian HIV Cohort Study, Innsbruck, Austria, 2Medical University Innsbruck, Innsbruck, Austria, 3AKH Linz, Linz, Austria, 4Medical University of Vienna, Vienna, Austria, 5LKH Graz West, Graz, Austria, 6University Hospital Salzburg, Salzburg, Austria, 7LKH Klagenfurt, Klagenfurt, Austria
Background: The objective of this study was to characterize the resurgence of syphilis in the Austrian HIV Cohort Study between 2002 and 2010.
Methods: Demographic data and syphilis diagnoses were collected from electronic medical records in 6 HIV treatment centers. All active cases of syphilis in a year added up to the prevalence of syphilis. A case of syphilis was considered incident when previous negative serology or successful treatment were documented.
Results: The analysis included 3426 patients with 14612 years of follow-up. Overall, prevalence of syphilis increased from 3.6 cases per 1000 person-years (c/py) in 2003 to 42.5 in 2006, 24.7 in 2007, 25.3 in 2008, and 22.1 in 2009. In men who have sex with men (MSM), prevalence of syphilis increased from 8.2 c/py in 2003 to 107.8 in 2006, 69.3 in 2007, 80.9 in 2008, and 59.7 in 2009. In women, prevalence of syphilis was 1.7 c/py in 2003, 8.5 in 2006, 2.7 in 2007, 0.0 in 2008, and 3.3 in 2009.
Syphilis incidence increased from 1.5 c/py in 2003 to 14.6 in 2006, 14.4 in 2007, 14.9 in 2008, and 12.7 in 2009. In MSM, syphilis incidence increased from 4.9 c/py in 2003 to 39.5 in 2006, 41.6 in 2007, 51.4 in 2008, and 35.4 in 2009. In women, syphilis incidence was 0 c/py in 2003, 2.8 in 2006, 2.7 in 2007, 0 in 2008, and 1.7 in 2009.
Among MSM, with or without incident syphilis, no differences in therapy related factors, CD4 count or age have been found. Men not having sex with men showed almost identical prevalence and incidence rates as women.
Conclusions: Syphilis has re-emerged in response to behaviour change and may be a harbinger of increasing rates of HIV infection among MSM. More efforts should be undertaken to better understand factors associated with the observed increases.