Background The incidence of syphilis has been increasing worldwide in the last 20 years, and disproportionately affecting people living with HIV. Additionally, several jurisdictions have reported increasing incidence of ocular syphilis (OS). If untreated or treatment is delayed, OS can lead to permanent blindness. We assessed characteristics of OS cases in British Columbia (BC), and sought to identify risk factors that may be associated with OS diagnosis, including factors related to HIV co-infection (e.g. CD4 count. viral load).
Methods This case-control study matched OS cases to syphilis controls (1:4) diagnosed in BC between January 2010 – March 2018. Demographic and clinical data were extracted from the provincial sexually transmitted infection database and analyzed using the chi-squared test. A multivariate logistic model was developed to assess factors associated with OS.
Results Between 2010–2018, 5681 syphilis cases were diagnosed in BC, including 61 (1.1%) diagnosed with OS. The proportion of syphilis cases with OS increased from 0.48% in 2010 to 2.99% in 2018 (P≤0.05). Among OS cases, median age was 47 years, 88.5% were male and the most common ophthalmologic diagnosis was panuveitis (44.3%). At the time of syphilis diagnosis, 50.8% of OS cases were HIV-positive compared to 25.8% of controls (P≤0.001). Among individuals with HIV co-infection, OS cases had higher viral loads (42.9% vs 79.7% were suppressed; P≤0.001) and lower median CD4 counts (470 vs 615 cells/mm3 ;P≤0.05) than controls. Factors associated with OS were primary/secondary stage of syphilis (adjusted odds ratio [aOR] 4.06; 95% confidence interval [CI] 1.52–10.8), early latent stage of syphilis (aOR 3.71; 95%CI 1.39–9.95), and HIV-positive serostatus (aOR 2.49; 95%CI 1.27–4.88).
Conclusion OS incidence and proportion increased over the study period in BC. These findings highlight the importance of vigilance for OS, particularly those in the early stages of syphilis and those living with HIV, to avoid diagnostic and treatment delays.
Disclosure No significant relationships.
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