Prevalence of Chlamydia trachomatis among young German adolescents, 2005-06

Background: Chlamydia trachomatis prevalence among 12-17-year-old adolescents in Germany was determined in the present study. Methods: A random age-stratified sample of 1815 urine specimens of boys and girls was selected from a population-based nationwide health survey conducted in 2003-06. Urine samples were pooled and tested for chlamydia using strand displacement amplification. Positive pools were individually retested. Prevalence, prevalence ratios (PR) and corresponding 95% confidence intervals (CI) were calculated. Associations between infection and socio-demographic factors (age, sex, place of residence), sexual activity (defined by oral contraceptive use or gynaecologist visits) and abdominal pain among females were examined in univariate analysis. Results: Sixteen samples (0.9% 95% CI: 0.5-1.3%), all from 15-17-year olds, were positive for chlamydia. Prevalence increased with age to 2% (95% CI: 0.8-3.2%) among 17 year olds and was higher among girls than boys (1.8% v. 0.1%; P < 0.001). A total of 4.6% (95% CI: 1.4-7.7%) of sexually active girls aged 17 were infected and 5/7 of them had no regular abdominal pain. Of all girls with abdominal pains, 52% had visited gynaecologists. Prevalence of infection was higher among those with pains than those without (PR = 3.8, 95% CI: 1.3-11.0). Conclusions: This is the first nationwide study based on a representative sample of boys and girls to measure chlamydia prevalence among adolescents in Germany. Prevalence in Germany is consistent with other countries. Among sexually active females, prevalence was comparable to screening thresholds. As gynaecological visits were common among females, we recommend that gynaecologists should actively offer screening to sexually active females, which would strengthen the newly implemented screening for females under 25 years.