Epidemiology of Chlamydia trachomatis in Canada: systematic review and meta-analysis, 1981-2025.

BACKGROUND

This study aimed to systematically review and synthesize evidence on Chlamydia trachomatis prevalence in Canada, describe epidemiological patterns across populations and anatomical sites, and assess associations with prevalence.

METHODS

A systematic review of Chlamydia trachomatis prevalence studies was conducted and reported according to PRISMA guidelines. Random-effects meta-analyses generated pooled mean prevalence estimates, and meta-regression analyses explored epidemiological and methodological predictors of prevalence variation.

RESULTS

A total of 169 publications were included, contributing 437 prevalence measures spanning 1981-2025. The pooled mean prevalence in the general population was 4.4% (95% CI: 3.6-5.2%) for current urogenital infection and 50.3% (95% CI: 44.5-56.1%) for ever infection. Among men who have sex with men and transgender people, prevalence estimates were 1.8% (95% CI: 0.6-3.5%) for urogenital infection, 6.6% (95% CI: 3.7-10.1%) for anorectal infection and 0.7% (95% CI: 0.0-2.1%) for oropharyngeal infection. Prevalence was substantially higher among symptomatic populations, reaching 18.6% (95% CI: 9.3-30.2%) in women and 24.3% (95% CI: 13.7-36.7%) in men. Meta-regression analyses explained >40% of the observed variation in prevalence, indicating that prevalence was approximately 30% lower among individuals aged ≥25 years compared with those aged <25 years, with no significant sex differences. Prevalence declined over time at a relative rate of 3% per year.

CONCLUSIONS

Chlamydia trachomatis prevalence in Canada is comparable to global levels. The ongoing persistence of infection underscores the need to enhance public health responses and expand investment in vaccine development as a cornerstone of long-term prevention and control.