The purpose of this study is to determine if, among women who were treated for a prior chlamydial infection, home-based, self-collected vaginal swabs can increase rescreening for chlamydia in comparison with rescreening in the clinic. The study design is two randomized trials with enrollment at multiple family planning clinics and sexually transmitted disease (STD) clinics following a common protocol.

The study consists of two complementary trials, denoted as Part A and Part B. In Part A, women/girls who had a positive test for chlamydia will be enrolled when they visit the study clinics for treatment. After written informed consent is obtained, women will be randomly assigned to the Clinic Group, in which they will be advised to return to the clinic for rescreening for chlamydia, or the Home Group, in which women will be asked to collect a vaginal swab at home and mail it to the study laboratory for chlamydia testing. In part B, women who were tested and empirically treated for a chlamydial infection will be called if their tests were positive. Enrollment will be offered over the phone after verbal consent. Rescreening will be scheduled 3 months after treatment of the initial infection for women in both trials.

Inclusion Criteria:

• Women/girls with a lab-confirmed genital chlamydia infection

Exclusion Criteria:

• Women who are pregnant, or are trying to conceive in the following 3 months.
• Women who are planning to move in the following 3 months or currently living outside the study areas.
• Inability to understand spoken English adequately to assure informed consent and compliance with study procedures.
• Self-reported HIV infection; other serious illnesses or disability.
• Self-reported allergy to macrolide antibiotics such as azithromycin.
• Referrals from providers or clinics other than the STD or family planning clinics, unless women are re-tested at the STD clinics and test positive for chlamydia.