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Urine-based testing for Chlamydia trachomatis among young adults in a population-based survey in Croatia: Feasibility and prevalence

Ivana Božičević1*, Ivana Grgić2, Snježana Židovec-Lepej2, Jurja-Ivana Čakalo1, Sanja Belak-Kovačević2, Aleksandar Štulhofer3 and Josip Begovac2

Author Affiliations

1 WHO Collaborating Centre for Capacity Development in HIV Surveillance; School of Medicine, Zagreb, Croatia

2 University Hospital for Infectious Diseases, Zagreb, Croatia

3 Faculty of Humanities and Social Sciences, Zagreb, Croatia

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BMC Public Health 2011, 11:230  doi:10.1186/1471-2458-11-230

Published: 14 April 2011



We assessed the feasibility of collecting urine samples for testing on genital Chlamydia trachomatis infection in a population-based survey, and prevalence of this infection among young people aged 18-25 in Croatia. In Croatia, as in the other countries of Eastern Europe, there is a lack of data on prevalence of C trachomatis in the general population, including young adults.


We sampled participants using a nationally representative, multi-stage stratified probability sample of young men and women. Detection of C trachomatis DNA in urine samples was performed by using a real-time PCR assay COBAS® TaqMan® CT Test, v2.0.


Overall, 1005 young adults participated in the behavioural part of the survey, and 27.9% men and 37.5% women who were sexually experienced agreed to provide urine samples for testing on C trachomatis. Using multivariate analysis, women were significantly more likely to provide urine samples than men (aOR = 1.53, 95% CI 1.14-2.06) as were those who reported no condom use at last intercourse (aOR = 1.95, 95% CI 1.44-2.62). Prevalence of C trachomatis infection among those who were sexually experienced was 7.3% in men and 5.3% in women.


Population-based surveys that use probabilistic sampling are a feasible way to obtain population estimates of C trachomatis prevalence among young adults in Croatia, but it is challenging to obtain an adequate response rate. The prevalence of C trachomatis among young adults in Croatia found in this study was higher than that found in other European countries with similar survey response rates.