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Patterns of syphilis testing in a large cohort of HIV patients in Ontario, Canada, 2000–2009

Ann N Burchell12*, Vanessa G Allen3, Veronika Moravan1, Sandra Gardner12, Janet Raboud24, Darrell HS Tan5, Ahmed M Bayoumi678, Rupert Kaul8, Tony Mazzulli1239, Frank McGee10, Peggy Millson2, Robert S Remis23, Sean B Rourke1116 and the OHTN Cohort Study Research Team

Author Affiliations

1 Ontario HIV Treatment Network, Suite 600, 1300 Yonge Street, Toronto, Ontario M4T 1X3, Canada

2 Dalla Lana School of Public Health, University of Toronto, Toronto, Canada

3 Public Health Laboratories, Public Health Ontario, Toronto, Canada

4 Toronto General Research Institute, University Health Network, Toronto, Canada

5 Division of Infectious Diseases, St. Michael’s Hospital, Toronto, Canada

6 Centre for Research on Inner City Health, The Keenan Research Centre in the Li KaShing Knowledge Institute, St. Michael’s Hospital, Toronto, Canada

7 Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada

8 Department of Medicine, University of Toronto, Toronto, Canada

9 Mount Sinai Hospital, Toronto, Ontario, Canada

10 AIDS Bureau, Ontario Ministry of Health and Long Term Care, Toronto, Canada

11 Department of Psychiatry, University of Toronto, Toronto, Canada

12 Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada

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BMC Infectious Diseases 2013, 13:246  doi:10.1186/1471-2334-13-246

Published: 28 May 2013



Since 2000, reported syphilis cases increased ten-fold in Canada, particularly among men who have sex with men (MSM) co-infected with HIV. We characterized temporal patterns of of syphilis testing in a large cohort of HIV patients in Ontario, Canada.


We analyzed data from a multi-site cohort of people in HIV care from 2000 to 2009. Data were obtained from medical charts, interviews and record linkage with the syphilis test database at the Public Health Ontario Laboratories. We estimated the proportion that had syphilis testing at least once per year and the period and annual prevalence of reactive tests.


Among 4232 participants, the annual proportion tested rose from 2.7% (95%CI 1.9, 3.5) in 2000 to 54.6% (95%CI 52.9, 56.3) in 2009. Testing was most common for participants who were men who have sex with men (MSM), aged <30, recently diagnosed with HIV, were antiretroviral treatment naive, had routine HIV lab testing at least twice in that year, or tested for syphilis in the preceding year. The proportion with at least one reactive test in 2000–09 was 21.0% (95%CI 19.4, 22.7) for MSM, 5.3% (95%CI 3.3, 7.4) for non-MSM males, and 2.6% (95%CI 1.2, 4.0) for women. Among MSM, the annual prevalence of reactive syphilis tests with high RPR titre (≥1:16) peaked at 3.8% in 2009.


The burden of syphilis co-infection rose considerably among HIV-positive MSM, such that by 2009, at least 1 in 5 men had laboratory evidence of current or past infection. Interventions may be needed to boost syphilis testing to achieve goals set by guidelines even in settings with universal health care.

Syphilis; HIV co-infections; Screening and diagnosis; Epidemiology