When is a chlamydia test of cure (TOC) done?

When to Perform Chlamydia Test of Cure

A chlamydia test of cure is generally not recommended for non-pregnant patients treated with the recommended regimens (azithromycin or doxycycline), unless therapeutic compliance is in question, symptoms persist, or reinfection is suspected. 1

General Recommendations

• Test of cure is NOT routinely needed for patients who complete treatment with azithromycin or doxycycline, as these regimens have high efficacy rates (97-98%) 1, 2
• Diagnostic testing performed less than 3 weeks after treatment completion can yield misleading results:
  • False-negative results may occur due to low organism numbers 3
  • False-positive results may occur due to detection of dead organisms 3, 1

Specific Situations When Test of Cure IS Recommended

• Pregnant women: Test of cure should be performed 3-4 weeks after completion of therapy, preferably using nucleic acid amplification test (NAAT) 1, 3
• Patients treated with erythromycin: Consider test of cure 3 weeks after completion of treatment due to lower efficacy compared to first-line regimens 3
• Questionable compliance: When there are concerns about patient adherence to the prescribed treatment regimen 1, 3
• Persistent symptoms: When symptoms continue despite appropriate treatment 1, 3
• Suspected reinfection: When there is concern about possible reexposure to untreated partners 1, 3

Timing of Test of Cure

• If performing a test of cure, it should be done no earlier than 3 weeks after completion of therapy 3, 1
• Testing before 3 weeks may detect residual nucleic acid from dead organisms, leading to false-positive results 3, 4
• Research shows that chlamydial rRNA can still be detected in 21% of women 14 days after treatment with azithromycin, supporting the recommendation to wait at least 3 weeks 4

Retesting vs. Test of Cure

• Retesting (which is different from test of cure) is recommended for all patients approximately 3 months after treatment due to high rates of reinfection 1
• The Centers for Disease Control and Prevention recommends that all women with chlamydial infection should be retested approximately 3 months after treatment 1
• Providers should retest all women treated for chlamydial infection whenever they next seek medical care within the following 3-12 months, regardless of whether the patient believes their partners were treated 1

Cautions and Pitfalls

• Be aware that intermittent positive test results can occur over time after treatment, which may complicate interpretation of test of cure results 5
• Distinguish between test of cure (to confirm treatment success) and retesting (to detect reinfection) 1
• For pregnant women, treatment failure can have serious consequences for both mother and infant, making test of cure particularly important in this population 3, 6

Treatment Considerations

• First-line treatments (azithromycin 1g single dose or doxycycline 100mg twice daily for 7 days) have high efficacy rates and rarely require test of cure 2
• For rectal chlamydia infections, doxycycline appears more effective than azithromycin (95.5% vs 78.5% cure rate), which may influence decisions about test of cure 7