The primary objective is to prospectively follow 200 women with or at risk of cervicitis to determine the chlamydia-specific cellular responses that correlate with protection against incident infection. The hypothesis is that a positive IFN-y response by peripheral CD4+ T cells responding to stimulation with HSP60 will be significantly associated with protection from incident C. trachomatis infection.

A total of 200 women with or at high risk of having cervicitis will be prospectively followed for correlations between chlamydia-specific cellular responses and protection against incident infection.

At enrollment participants will undergo a history and physical examination; blood draw; and pelvic examination including collection of vaginal and cervical samples, STD testing and endometrial biopsy.

Participants will have follow up visits conducted at 1, 4, 8 and 12 months following enrollment. At the follow-up visits, participants will undergo a repeat history and physical, blood draw and pelvic examination including collection of vaginal and cervical samples and STD testing.

The study design will allow comprehensive identification of the antigen-specific cell mediated immune responses most strongly associated with protection against C. trachomatis infection.

The primary objective is to prospectively follow 200 women with or at risk for cervicitis to determine the chlamydia-specific cellular responses that correlate with protection against incident infection.

Inclusion Criteria

1. Women 15-35 years of age. Note: Minors must have written informed consent from her parent/legal guardian to participate.

2. At least one of the following:

   1. Current , untreated endocervical C. trachomatis infection.
   2. Mucopurulent cervicitis: defined by the presence of yellow or green endocervical mucopurulent discharge and/ or easily induced endocervical bleeding (bleeding when the first swab is placed in the endocervix).
   3. Sexual contact with a male partner (regardless of condom use) recently diagnosed (within the past 3 months) with C. trachomatis and/or non-gonococcal urethritis.

Exclusion Criteria:

1. Pregnant or nursing a baby. Note: a urine pregnancy test will be done at enrollment. Result must be negative to participate in the study.
2. Gynecologic surgery or surgical abortion in preceding 2 months of enrollment.
3. Allergy to any of the study medications and/or derivatives (cephalosporins, azithromycin, erythromycin, any macrolide or ketolide antibiotic) or Type 1 hypersensitivity allergic reaction to penicillin.
4. Systemic or vaginal antibiotic therapy in preceding 7 days of enrollment.
5. Prior hysterectomy.
6. Menopause.
7. Any condition, in the opinion of the investigator that would interfere with the participant's safety or with study outcomes.
8. Participation in any study involving an investigational product in the past 30 days or anticipation of participation in any study using an investigational product in the next 30 days.
9. Previous participation in this study.

Women positive for chlamydia or at high risk of chlamydia infection.