PREdictive value of the Self-triagecard and Chlamydia trachomatis positivity rate in vocational School students (PRESS-study)

Chlamydia trachomatis (CT) is the most prevalent bacterial sexual transmitted
disease (STDs) with major public health consequences due to its frequent
asymptomatic nature, its high prevalence among adolescents and its reproductive
morbidity. The incidence of CT infections is currently increasing. Especially
CT positivity rates on schools for low and intermediate education seem to be
high. One Rotterdam study showed a prevalence of 24.5% compared to our STD
outpatient clinic and general sexual active 15-29 year-olds 8.9% vs. 2.3%. STD
testing on schools showed highly acceptable in international studies although
CT positivity rates are not generalizable to Dutch schools. Based on a previous
Dutch population study, a prediction rule for CT infection was assessed with
potential value on different screening settings. Based on this prediction rule
we designed a self-triagecard for individuals to assess their risk profile on
CT.

This study assesses the prevalence of CT and GC in vocational school students
and assesses the validity and feasibility of the self-triagecard as a method to
efficiently identify and treat CT positive youth and limit the spread of CT.

Design of the study:
This is an intervention study . We will randomize itwo groups:
group 1) intervention group
Questionnaire and self-triagecard with diagnostic CT and GC test
group 2) non-intervention group
Questionnaire and diagnostic CT test

The intervention is filling in a 7-item self-triagecard and obtaining
testadvice accordingly.

The major advantage is an accurate diagnosis for CT and GC and free treatment.
In addition a STD education at school is provided. Procedures to take
biological specimens are minimally invasive.
Possible disadvantages are the time-investment to fill out questionnaires and
to take a biological sample (FCU/SVS). Possible stigmatization is greatly
reduced because all students in the classroom receive the same STD education.
This study is deemed to be mainly conducted by classrooms since the expected
contamination-effect of the intervention (self-triagecard) is large and this
will dilute any existing effect. However, to avoid any stigmatization or
grouppressure, we provide the opportunity to fill out questionnaires and take
biological materials outside the school/class and return them the next day.
Students without sexual experience will also be included in the study to reduce
potential stigmatisation in classes.
To ensure that it is not obvious to other subjects who does test and who does
not test, all subjects are asked to return the test tubes, whether filled or
not, in the given coded envelope.