Recently in BC, the number of infectious syphilis cases in gay, bisexual and other men who have sex with men (MSM) has been increasing dramatically, particularly among men living with HIV infection. This trend is not unique to BC, and has been reported elsewhere in Canada as well as internationally.
Syphilis is curable by antibiotics. However, if it is not diagnosed and treated early on, syphilis can lead to serious complications including permanent neurological damage (neurosyphilis) and can be fatal. In the past few years, public health and community agencies have aimed to increase awareness among health care providers and MSM of the increase in syphilis in BC. This includes promoting regular syphilis testing, timely treatment, and testing of sexual partners.
In this post, we provide an update on infectious syphilis cases among MSM in BC through to the end of 2013.
Diagnosis, clinical follow-up, and surveillance of syphilis in BC is centrally managed at the BCCDC. Surveillance data on infectious syphilis cases (i.e., primary, secondary and early latent syphilis) among MSM between 2004 and 2013 were extracted from the Provincial STI Database and the enhanced syphilis surveillance databases at the BCCDC.
(Note: 2013 numbers are current as of February 2014, and are not considered final).
Infectious syphilis cases continued to increase among MSM – from 309 cases in 2012 to 474 cases in 2013 – representing 84% of all infectious syphilis cases in BC in 2013.
The majority of cases continue to be identified among MSM in the Lower Mainland (96%). Of the 2013 MSM cases, 46% were diagnosed with either primary or secondary syphilis and 54% with early latent syphilis. Neurosyphilis was diagnosed in 15 men with infectious syphilis (up from 11 cases in 2012). 18% (87 cases) of MSM diagnosed with infectious syphilis in 2013 had been previously diagnosed with syphilis in the past 2 years.
In 2013, two-thirds (64%) of cases were MSM known to be HIV positive, and 24 men (5%) were diagnosed with HIV infection around the time of their syphilis diagnosis (up from 16 cases in 2012).
Overall, while the number of infectious syphilis cases increased in 2013 among all sub-groups of MSM, the percentage of cases in each sub-group examined was generally consistent with longer-term trends.
Implications for practice
The increase in infectious syphilis cases among MSM in BC continued unabated in 2013. The data suggests growth of the ongoing epidemic in 2013 (i.e., we found no substantial increases in sub-groups of MSM to suggest the epidemic was shifting to new susceptible groups).
Due to the growth of the epidemic, we observed more neurosyphilis cases in 2013, and an increase in the number of men diagnosed with HIV and syphilis at the same time. This may be related to the synergistic effect of syphilis and HIV epidemics, where syphilis lesions can lead to a higher risk of HIV infection or transmission.
Infectious syphilis among MSM remains a public health priority. Providers are encouraged to offer regular syphilis testing to their MSM clients: up to every 3 to 6 months for men who are sexually active, which can be incorporated into routine bloodwork for men with HIV.
While testing, treatment, and partner notification remain the cornerstone of the public health response to syphilis epidemics, these data suggest a need for continued awareness of syphilis among MSM and providers. Efforts to develop new interventions for prevention, particularly for HIV positive men or men previously diagnosed with syphilis, must continue.
For further information
Daphne Ling, Elsie Wong (Epidemiology & Surveillance); Richard Lester, Carolyn Montgomery (Provincial STI Clinic); BCCDC, Clinical Prevention Services