Chlamydia trachomatis-infecties in 4 regio's in Nederland: Resultaten van een bevolkingsonderzoek via de GGD en implicaties voor screening

Objective. To determine the prevalence of Chlamydia trachomatis in people aged 15-29 years and the feasibility of screening through municipal health services. Design. Descriptive. Method. In 2002/'03 a home-sampling kit was sent by mail to 21,003 randomly selected people aged 15-29 years in 4 regions. Urine samples were returned by mail and tested by polymerase chain reaction (PCR). Treatment of those who tested positive was done by general practitioners, a clinic of the municipal and public health services or a clinic for sexually transmitted diseases. Prevalence was determined after adjusting for gender, age and residence. Risk factors were identified using uni- and multivariate analysis and results were converted to a total risk score from which the chance of having a C. trachomatis infection could be calculated. Results. Of the 20,495 persons of the study population 10,610 persons responded (52%): 11% sent in a refusal card and 41% sent in urine. The prevalence of C. trachomatis was 2.0% (95% CI: 1.7-2.3); 2.5% (95% CI: 2.0-3.0) in women and 1.5% (95% CI: 1.1-1.9) in men. Of all 165 cases, 91% were treated. Prevalence was lower in rural areas (0.6%; 95% CI: 0.1-1.1) compared to very highly urbanized areas (3.2%; 95% CI: 2.4-4.0). In addition to degree of urbanization, infection was associated with ethnicity, total number of sex partners and symptoms. The resulting prediction model discriminated well. Conclusion. In people aged 15-29 years, 2% were infected with C. trachomatis. The chance of infection was dependent on various risk factors. The prediction model offers opportunities for selective screening.