National prevalence estimates of chlamydia and gonorrhoea in the Netherlands (PECAN): comparison of two national cross-sectional surveys

OBJECTIVES: National prevalence estimates of chlamydia and gonorrhoea are essential to inform public health strategies and support evidence-based policy development. The aim was to generate national prevalence chlamydia and gonorrhoea estimates in 2022/2023, identify associated risk factors and compare prevalence over time. METHODS: Five years after the first survey in 2016/2017, a second national cross-sectional probability sample survey about sexual health among men and women aged 16-34 years in the Netherlands was conducted between October 2022 and March 2023. Sexually active survey participants were invited to participate in the prevalence study and received a home-based sampling kit. Returned samples were tested for chlamydia and gonorrhoea in a laboratory (ie, nucleic acid amplification test). Weighting techniques were used to correct for selective non-response. Multivariable logistic regression analyses were performed to identify risk factors of infection. RESULTS: Of 6277 survey participants invited for the prevalence study, 1142 (18.2%) returned a specimen. The weighted overall chlamydia prevalence was 3.5% (95% CI 2.3% to 5.4%), and prevalence was higher in younger age groups (<25 vs ≥25 years). Due to low numbers in other groups, risk factor analysis was only possible among women aged 18-24 years, where risk factors for chlamydia included being <20 years, vocational education, no steady relationship and condomless sex. As in 2016/2017, no gonorrhoea cases were detected in 2022/2023. Chlamydia prevalence and associated risk factors did not change, except for higher prevalence among university-educated individuals in 2022/2023. DISCUSSION: Chlamydia prevalence among young sexually active men and women in the Netherlands remained stable between 2016/2017 and 2022/2023, with higher prevalence observed in younger age groups in both studies. Given recent changes in chlamydia testing guidelines in the Netherlands towards more restrictive testing of asymptomatic individuals, probability sample surveys with laboratory-confirmed STI testing are crucial for monitoring prevalence trends and evaluating public health policy.