Background
Epidemiology of genital infections with Chlamydia trachomatis and further complications
Prevention strategies in France and in other European countries
Gaps in knowledge
Main objective
Secondary objectives
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To determine the baseline prevalence and the incidence of Ct infection
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To improve knowledge of the natural history of Ct infection in young women, including rate and timing of progression to PID, as well as the incidence of Ct reinfection
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To investigate the relationship between host immunogenetics (SNPs), Ct clearance, persistence, and development of late complications (PID) as an explanatory factor for inter-individual heterogeneity in Ct susceptibility and infection progression.
Methods/design
Design/setting
Participants
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Inclusion criteria
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Female student registered at a French university participating in the i-Share cohort
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Aged 18 to 24 years
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Sexually active
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Signed written informed consent
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Covered by the French National Health Insurance programme
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Non-inclusion criteria
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Reported pregnancy
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Intervention
Experimental group
Control group
Blinding
Recruitment, randomisation, follow-up and data collection
Initial visit
Randomisation
Follow-up
Final visit
Outcomes
Primary endpoint
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Probable PID: Clinical diagnosis of PID (pelvic pain, cervical motion tenderness, uterine or adnexal tenderness)
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Confirmed PID: Clinical diagnosis of PID and one of the following criteria: laparoscopic abnormalities consistent with PID, endometrial biopsy with histopathologic evidence of endometritis, pelvic ultrasound showing thickened tubal wall (>8 mm), tubal fringes or free pelvic fluid
Secondary endpoints
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Prevalence of Ct infection in participants at baseline (intervention and control groups)
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Incidence of first Ct infection in participants with a negative Ct test result at baseline (intervention and control groups)
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Incidence of first PID (intervention and control groups)
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Duration of Ct infection (6 or 12 months or over 18 months because the time window between each assessment is 6 months); proportion of infections associated with a diagnosis of PID (whether at a previous visit or concurrently) and time to development of PID since Ct infection; proportion of spontaneous Ct infection resolution (control group), defined as a Ct-negative sample after one or more Ct-positive samples
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Incidence of reinfections (intervention and control groups); an algorithm to differentiate between Ct reinfection, treatment failure and persistent infection [21] will be developed on the basis of typing (as described below in laboratory analyses), treatment, partner notification and change of partner
Materials/laboratory analyses
Sample size
Statistical analyses
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Annual incidence of Ct infection based on the first recorded Ct infection among participants Ct-negative at baseline in both groups
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Among participants in the control group with incident Ct infection (participants Ct-negative at baseline), proportions (and 95% CIs) of Ct infections with spontaneous resolution and of Ct infections evolving towards PID; estimation of the duration of Ct infection (from Ct detection to clearance) and time to develop PID (time between incident Ct infection and incident PID, defined as from 3 months before Ct detection because time windows correspond to 6 months, to the onset of PID symptoms)
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Among participants in both groups who have cleared Ct infection at least once, incidence of Ct reinfection and comparison between the treated (intervention) and untreated (control) groups
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Among participants in the control group, exploratory logistic regression to assess whether 50 immunogenetic biomarkers can predict Ct persistence and occurrence of PID