After declining to historic lows in the mid-1990s, rates of infectious syphilis in BC increased, at first predominantly among street-involved populations in Vancouver’s Downtown Eastside, then more recently among gay, bisexual, and other men who have sex with men (MSM). As in other jurisdictions throughout North America, MSM now make up the majority of infectious syphilis cases in the province. Here we present trends over time and characteristics of the MSM cases.
Methods
Diagnosis, clinical follow-up, and surveillance of syphilis in BC is centrally managed at the BC Centre for Disease Control. Surveillance information on infectious syphilis cases among MSM between 2003 and 2012 were extracted from the Provincial STI Database and the enhanced syphilis surveillance databases at the BCCDC.
Findings
Between 2003 and 2012, a total of 1617 infectious syphilis cases were diagnosed among MSM in BC. During this period, trends fluctuated, however, there was no sustained decrease in cases among MSM. Notably, the number of cases among MSM doubled in the past year, from 152 in 2011 to 306 in 2012.
- The majority of the MSM cases in 2003-2012 were in the Lower Mainland (93%).
- The average age was 41 years.
- Seventy percent (70%) were Caucasian, 7% Asian, and 6% Latino.
- Of those with known HIV status, 61% were HIV-positive.
- Half of the cases were diagnosed by private physicians (GPs).
- Twenty-one percent (21%) were diagnosed in the primary stage, 32% in the secondary stage, 47% in the early latent stage (asymptomatic).
- Five percent (5%) were co-diagnosed with neurosyphilis.
- Fifteen percent (15%) of the individuals were diagnosed with more than one syphilis infection during this 10-year period.
We divided the recent epidemic into phases of growth and decline to identify any shifts in the profile of cases; however, the general characteristics of these MSM cases did not change substantially over the past 10 years.
Interpretation and implications
A recent increase in infectious syphilis cases was observed among gay, bisexual, and other MSM in BC, with nearly two-thirds of cases among HIV-positive men. Despite fluctuations in trends between 2003 and 2012, characteristics of MSM cases have generally remained stable.
Syphilis is preventable and can be treated. However, if syphilis is not diagnosed and treated at an early stage, there can be serious complications such as neurological disease. Several factors may be contributing to the ongoing syphilis epidemic in BC. A better understanding of core sexual networks—with a focus on HIV co-infection and repeat syphilis infection—will be instrumental to informing further response to the epidemic in MSM. Testing is a key strategy and all sexually active gay and bisexual men should get tested regularly for syphilis and other STI.
For further information
A companion blog entry describes the clinical presentation of primary and secondary syphilis. Information for public/clients about syphilis can be found here. For more detailed surveillance data on syphilis and other reportable STI in BC, see the Annual Surveillance Reports on the BCCDC website.
Acknowledgements
Monika Lindegger, Teddy Consolacion, Mark Gilbert (Epidemiology & Surveillance); Richard Lester (Provincial STI Clinic); BCCDC, Clinical Prevention Services