Low prevalence of Chlamydia trachomatis infection in asymptomatic young Swiss men.
BACKGROUND
Prevalence and risk factors for Chlamydia trachomatis infection among young men in Switzerland is still unknown. The objective of the present study was to assess prevalence and risk factors for C. trachomatis infection in young Swiss men.


METHODS
517 young Swiss men were enrolled in this cross-sectional study during their compulsory military recruitment. Participants completed a questionnaire and gave urine samples which were screened for C. trachomatis DNA by PCR. Genotyping of positive samples was done by amplification and sequencing the ompA gene.


RESULTS
The prevalence of chlamydial infection among young Swiss male was 1.2% (95% confidence interval [95%CI], 0.4-2.5%). C. trachomatis infection was only identified among the 306 men having multiple sexual partner. Although frequent, neither unprotected sex (absence of condom use), nor alcohol and drug abuse were associated with chlamydial infection. Men living in cities were more frequently infected (2.9%, 95%CI 0.8-7.4%) than men living in rural areas (0.5%, 95%CI 0.1-1.9%, p = 0.046). Moreover, naturalised Swiss citizens were more often positive (4.9%, 95%CI 1.3-12.5%) than native-born Swiss men (0.5%, 95%CI 0.1-1.7%, p = 0.003).


CONCLUSIONS
In comparison with other countries, the prevalence of chlamydial infection in men is extremely low in Switzerland, despite a significant prevalence of risky sexual behaviour. C. trachomatis infection was especially prevalent in men with multiple sexual partners. Further research is required (i) to define which subgroup of the general population should be routinely screened, and (ii) to test whether such a targeted screening strategy will be effective to reduce the prevalence of chlamydial infection among this population.
Baud
David
D
Institute of Microbiology, University Hospital Centre and University of Lausanne, Lausanne, Switzerland. david.baud@chuv.ch
Jaton
Katia
K
Bertelli
Claire
C
Kulling
Jean-Pierre
JP
Greub
Gilbert
G
D000293:Adolescent; D000328:Adult; D000437:Alcoholism; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D002690:Chlamydia Infections / Q000453:epidemiology* / Q000382:microbiology / Q000503:physiopathology; D002692:Chlamydia trachomatis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012307:Risk Factors; D017422:Sequence Analysis, DNA; D012725:Sexual Behavior; D011795:Surveys and Questionnaires; D013557:Switzerland / Q000453:epidemiology; D014556:Urine / Q000382:microbiology
D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; C078167:OMPA outer membrane proteins