CLINICAL ACTIONS:

Annual screening of all sexually active women aged <25 years for chlamydia is recommended, as is screening of older women at increased risk for infection (e.g., those who have a new sex partner, more than one sex partner, a sex partner with concurrent partners, or a sex partner who has an STD).

To diagnose a chlamydia infection:

• Obtain nucleic acid amplification testing (NAAT), which detects genetic material of C. trachomatis
  • Highly sensitive in first-catch urine samples and endocervical or vaginal swabs
  • Can be collected by a provider or a self-collected vaginal swab
  • Certain NAATs have been FDA-cleared for use on liquid-based cytology specimens (collected for Pap smears), however sensitivity may be lower than swabs

SYNOPSIS:

Chlamydial infection is the most frequently reported infectious disease in the United States, and prevalence is highest in persons aged ≤24 years. Several sequelae can result from C. trachomatis infection in women, the most serious of which include PID (pelvic inflammatory disease), ectopic pregnancy, and infertility. Some women who receive a diagnosis of uncomplicated cervical infection already have subclinical upper-reproductive–tract infection.

KEY POINTS:

Chlamydia treatment should be provided promptly for all persons testing positive for infection; treatment delays have been associated with complications

• Recommended Regimens
  • Azithromycin 1 g orally in a single dose or
  • Doxycycline 100 mg orally twice a day for 7 days

• Alternative Regimens
  • Erythromycin base 500 mg orally four times a day for 7 days or
  • Erythromycin ethylsuccinate 800 mg orally four times a day for 7 days or
  • Levofloxacin 500 mg orally once daily for 7 days or
  • Ofloxacin 300 mg orally twice a day for 7 days

• Routine pharyngeal screening for chlamydia is not recommended, but if C. trachomatis is detected in an oropharyngeal specimen treat with azithromycin or doxycycline
• Directly observe patient receiving therapy when single dose therapy is given
• To minimize disease transmission to sex partners, persons treated for chlamydia should be instructed to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen and resolution of symptoms if present
• To minimize risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all of their sex partners are treated
• Persons who receive a diagnosis of chlamydia should be tested for HIV, gonococcal infection, and syphilis
• Test-of-cure to detect therapeutic failure is not advised unless therapeutic adherence is in question, symptoms persist, or reinfection is suspected
  • Chlamydial NAATs at <3 weeks after completion of therapy is not recommended because the continued presence of nonviable organisms can lead to false-positive results
• Retest after 3 months
  • Recurrence may not be treatment failure but rather reinfection
  • In States where legally allowed (see ‘Related OBG Topics’ below), consider Expedited Partner Therapy (EPT) which allows the patient herself to provide medications to her partner when there are limited public health services to treat a partner, or concern that the partner will not have access to treatment
• Treat women with HIV with the same recommended regimen

PREGNANCY AND CHLAMYDIAL INFECTION

Risks in pregnancy include preterm labor, premature rupture of membranes and low birth weight with neonates at risk for conjunctivitis (ophthalmia neonatorum) and pneumonia. It is therefore imperative to screen and treat pregnant women with the following:

• Recommended Regimens
  • Azithromycin 1 g orally in a single dose
• Alternative Regimens
  • Amoxicillin 500 mg orally three times a day for 7 days or
  • Erythromycin base 500 mg orally four times a day for 7 days or
  • Erythromycin base 250 mg orally four times a day for 14 days or
  • Erythromycin ethylsuccinate 800 mg orally four times a day for 7 days or
  • Erythromycin ethylsuccinate 400 mg orally four times a day for 14 days

• Test-of-cure (preferably by NAAT) recommended at 3 to 4 weeks after completion of therapy and again after 3 months
• Diagnosis code: Chlamydia: A74.9  (pregnant) or A56.02 (nonpregnant)

Learn More – Primary Sources:

CDC: Chlamydial Infections in Adolescents and Adults

CDC: Chlamydia Fact Sheet for Your Patients

Related ObG Topics:

STI Screening in Pregnancy: CDC Recommendations

Screening for Sexually Transmitted Infections – Who, When and How Often?

Pelvic Inflammatory Disease – CDC Treatment Guidelines

The ABCs of PID Diagnosis – What You Need to Know

Sexually Transmitted Infections and Partner Notification