Factors Associated With Positive Post-Treatment STI Tests and Sexual Knowledge, Attitudes, Behaviors and Practices (ECART-IST)

November 9, 2026 updated by: Centre Hospitalier de Martigues

Factors Associated With a Positive Post-Treatment Test for Sexually Transmitted Infections Caused by Chlamydia Trachomatis and/or Neisseria Gonorrhoeae in Relation to Sexual Knowledge, Attitudes, Behaviors and Practices (KABP): A Prospective Longitudinal Single-Center Study

The goal of this study is to understand why some adults continue to test positive for chlamydia or gonorrhea after receiving antibiotic treatment.

The study will also explore whether sexual health knowledge, attitudes, behaviors, and practices are linked to positive test results after treatment.

The main questions this study aims to answer are:

How many participants test positive for chlamydia or gonorrhea four or eight weeks after treatment? Are differences in sexual health knowledge, attitudes, behaviors, and practices linked to positive test results? Are treatment adherence and sexual behaviors after treatment linked to positive test results? The study will include 238 adults diagnosed with chlamydia, gonorrhea, or both infections at the Centre Hospitalier de Martigues in France.

Participants will:

Receive standard antibiotic treatment as part of their usual medical care. Answer a questionnaire about their sexual health knowledge, attitudes, behaviors, and practices.

Attend two follow-up visits, approximately four and eight weeks after their initial visit.

Provide samples for additional laboratory tests to check for chlamydia or gonorrhea at both follow-up visits.

Answer questions about their treatment and sexual behaviors during follow-up. The researchers will compare participants who test positive after treatment with those who test negative. This comparison may help identify factors linked to persistent infection or a new infection.

Participation is voluntary. The study does not involve experimental medication or changes to the usual antibiotic treatment.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

**Background and Rationale**

Chlamydia trachomatis and Neisseria gonorrhoeae are common sexually transmitted infections (STIs) and remain important public health concerns.

Although effective antibiotic treatments are available, some individuals continue to have positive laboratory tests after treatment. These positive results may be associated with persistent infection, reinfection, or other factors.

Sexual knowledge, attitudes, behaviors, and practices may influence the risk of a positive post-treatment test. However, the relationship between these factors and post-treatment test results remains insufficiently understood.

**Study Objectives**

The primary objective of ECART-IST is to identify factors associated with a positive post-treatment nucleic acid amplification test (NAAT/PCR) for Chlamydia trachomatis and/or Neisseria gonorrhoeae at week 4 and/or week 8, according to the dimensions of a Knowledge, Attitudes, Behaviors, and Practices (KABP) questionnaire.

Secondary objectives include describing participants' sexual health knowledge and behaviors, estimating positive test rates at follow-up visits, and exploring associations with treatment adherence, sexual re-exposure, and other clinical or sociodemographic characteristics.

**Study Design and Procedures**

ECART-IST is a prospective, longitudinal, single-center study conducted at the Centre Hospitalier de Martigues, France.

The study aims to enroll 238 adults with a confirmed Chlamydia trachomatis and/or Neisseria gonorrhoeae infection.

Participants will receive antibiotic treatment according to standard clinical practice. No experimental medication or modification of the usual treatment strategy is planned.

At the initial visit, researchers will collect sociodemographic, clinical, microbiological, and behavioral information. Participants will also complete a KABP questionnaire.

Two additional follow-up visits are scheduled at week 4 (plus or minus 7 days) and week 8 (plus or minus 7 days).

At each follow-up visit, participants will undergo a post-treatment NAAT/PCR test. Researchers will also collect information about treatment adherence, sexual behaviors, possible re-exposure, and changes in KABP questionnaire responses.

When appropriate and technically feasible, bacterial cultures and antimicrobial susceptibility testing may also be performed.

**Statistical Analysis**

The proportion of participants with a positive post-treatment test at week 4 and/or week 8 will be estimated with a 95% confidence interval.

Researchers will compare participants with positive and negative follow-up tests.

Univariable analyses will explore associations between the study outcome and KABP scores, clinical characteristics, treatment adherence, and sexual behaviors.

Multivariable logistic regression will be used to identify factors independently associated with positive post-treatment tests. Results will be expressed as adjusted odds ratios with 95% confidence intervals.

Longitudinal changes in KABP questionnaire scores may also be analyzed using statistical methods appropriate for repeated measurements.

**Expected Contribution**

This study aims to improve understanding of the behavioral, clinical, and microbiological factors associated with positive STI tests after treatment.

Its findings may help healthcare professionals improve patient education, prevention strategies, and follow-up care for people diagnosed with chlamydia or gonorrhea.

Study Type

Interventional

Enrollment (Estimated)

238

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • France
    • Bouches du Rhone
      • Martigues, Bouches du Rhone, France, 13500
        • Recruiting
        • Centre Hospitalier de Martigues
        • Contact:
        • Principal Investigator:
          • Erika KURZAWA, doctor

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

Adults aged 18 years or older, regardless of sex.

Confirmed Chlamydia trachomatis and/or Neisseria gonorrhoeae infection diagnosed by nucleic acid amplification testing (NAAT/PCR) or culture at the Centre Hospitalier de Martigues.

Symptomatic or asymptomatic individuals receiving medical care for a sexually transmitted infection.

No antibiotic treatment targeting Chlamydia trachomatis or Neisseria gonorrhoeae within the 7 days preceding enrollment.

Individuals who have received written and oral information about the study and have provided free, informed, written consent after an appropriate reflection period.

Individuals agreeing to attend the scheduled follow-up visits.

Individuals able to read, understand, and complete the study questionnaires in French, including the KABP questionnaire.

Individuals accepting the specific research procedures in accordance with applicable regulations.

Exclusion Criteria:

  • Individuals younger than 18 years.

Absence of microbiological confirmation of Chlamydia trachomatis and/or Neisseria gonorrhoeae infection by NAAT/PCR or culture.

Antibiotic treatment targeting Chlamydia trachomatis or Neisseria gonorrhoeae initiated before enrollment.

Individuals deprived of liberty by judicial or administrative decision.

Individuals under legal protection measures (guardianship, curatorship, or judicial protection) or otherwise unable to provide informed consent, in accordance with the study protocol.

Individuals who do not sufficiently understand French to receive study information or complete the questionnaires.

Individuals unable to comply with the scheduled follow-up visits or study-specific procedures.

Individuals who refuse to participate or decline to sign the informed consent form.

Individuals participating in another interventional study that may interfere with the objectives of ECART-IST.

Individuals whose medical condition or situation, as assessed by the investigator, makes optimal participation impossible or may compromise the quality of the collected data.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: ECART-IST Follow-up Cohort

Adults diagnosed with Chlamydia trachomatis and/or Neisseria gonorrhoeae infection will be enrolled in a single prospective follow-up cohort. All participants will receive standard antibiotic treatment as part of routine care. Additional follow-up assessments will be performed at weeks 4 and 8, including NAAT/PCR testing and KABP questionnaires. No experimental treatment or randomization is planned
Other: Sexual Health KABP Questionnaire

Participants will complete a structured questionnaire assessing sexual health knowledge, attitudes, behaviors, and practices (KABP) at baseline, week 4, and week 8. The questionnaire will explore factors potentially associated with positive post-treatment tests, including sexual behaviors and possible re-exposure to infection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of Participants With a Positive Post-Treatment NAAT/PCR Test at Week 4 and/or Week 8
Time Frame: Week 4 (±7 days) and Week 8 (±7 days) after enrollment

Percentage of participants with at least one positive nucleic acid amplification test (NAAT/PCR) for Chlamydia trachomatis and/or Neisseria gonorrhoeae at week 4 and/or week 8 after enrollment. The proportion will be calculated among evaluable participants and reported with a 95% confidence interval.
Week 4 (±7 days) and Week 8 (±7 days) after enrollment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of Participants With a Positive Post-Treatment NAAT/PCR Test at Week 4
Time Frame: Week 4 (±7 days) after enrollment

Percentage of evaluable participants with a positive nucleic acid amplification test (NAAT/PCR) for Chlamydia trachomatis and/or Neisseria gonorrhoeae at week 4 after enrollment, reported with a 95% confidence interval.
Week 4 (±7 days) after enrollment
Proportion of Participants With a Positive Post-Treatment NAAT/PCR Test at Week 8
Time Frame: Week 8 (±7 days) after enrollment

Percentage of evaluable participants with a positive nucleic acid amplification test (NAAT/PCR) for Chlamydia trachomatis and/or Neisseria gonorrhoeae at week 8 after enrollment, reported with a 95% confidence interval.
Week 8 (±7 days) after enrollment

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of Participants With Positive NAAT/PCR Tests at Both Week 4 and Week 8
Time Frame: Week 4 (±7 days) and Week 8 (±7 days) after enrollment

Percentage of evaluable participants with positive nucleic acid amplification tests (NAAT/PCR) for Chlamydia trachomatis and/or Neisseria gonorrhoeae at both week 4 and week 8 after enrollment. This measure describes repeated post-treatment test positivity, without automatically classifying it as persistent infection or reinfection
Week 4 (±7 days) and Week 8 (±7 days) after enrollment
Comparison of Post-Treatment Test Positivity Rates Between Chlamydia trachomatis and Neisseria gonorrhoeae Infections
Time Frame: Week 4 (±7 days) and Week 8 (±7 days) after enrollment

The proportions of participants with positive post-treatment nucleic acid amplification tests (NAAT/PCR) will be compared between Chlamydia trachomatis and Neisseria gonorrhoeae infections at week 4 and week 8. Positivity rates will be calculated separately for each infection and compared to identify potential differences between the two pathogens.
Week 4 (±7 days) and Week 8 (±7 days) after enrollment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centre Hospitalier de Martigues

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 29, 2026

Primary Completion (Estimated)

April 2, 2029

Study Completion (Estimated)

April 2, 2029

Study Registration Dates

First Submitted

November 9, 2026

First Submitted That Met QC Criteria

November 9, 2026

First Posted (Actual)

November 13, 2026

Study Record Updates

Last Update Posted (Actual)

November 13, 2026

Last Update Submitted That Met QC Criteria

November 9, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ECART-IST-2026-A01264-47
  • 2026-A01264-47 (Other Identifier: ANSM)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be made publicly available. Data collected during this study are pseudonymized and managed by the Centre Hospitalier de Martigues in accordance with applicable data protection regulations, including the GDPR. Access is restricted to authorized research personnel. Study findings may be published in scientific journals in aggregated form, without identifying individual participants.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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