How soon after treatment for syphilis do you retest?

Retesting After Syphilis Treatment

For primary and secondary syphilis, retest at 6 and 12 months after treatment; for latent syphilis, retest at 6,12, and 24 months. 1, 2

Standard Follow-Up Schedule by Stage

Early Syphilis (Primary and Secondary)

• Perform clinical and serologic evaluation at 6 and 12 months after treatment 1, 2
• If follow-up compliance is uncertain, more frequent testing at 3-month intervals is recommended 2
• A fourfold decline in nontreponemal test titers (RPR or VDRL) within 6-12 months indicates adequate treatment response 1, 3

Latent Syphilis

• Follow-up testing should occur at 6,12, and 24 months after treatment 1
• For late-latent syphilis specifically, monitor at 3,6,12,18, and 24 months to ensure at least a fourfold decline in titer 4
• Expect a slower serologic response compared to early syphilis, with fourfold decline occurring within 12-24 months 1, 5

HIV-Infected Patients Require More Intensive Monitoring

HIV-infected patients need substantially more frequent follow-up at 3,6,9,12, and 24 months after therapy 4, rather than the standard 6-month intervals used for HIV-negative patients 3. This is critical because:

• HIV-infected patients may have atypical serologic responses with poorer treatment outcomes 4
• CSF examination at 6 months after therapy may be recommended, though benefit is unproven 1
• These patients are at higher risk for neurosyphilis, particularly if RPR titers are ≥1:32 or CD4 counts are <350 cells/mm³ 6

Neurosyphilis Follow-Up

For patients treated for neurosyphilis, the monitoring schedule differs significantly:

• Repeat CSF examination at 6 months after completion of therapy 4
• If CSF pleocytosis persists, continue CSF examinations every 6 months until the CSF white blood cell count normalizes and CSF-VDRL becomes nonreactive 4
• The earliest indicator of treatment response is decline in CSF lymphocytosis, while CSF-VDRL may respond more slowly 4

Critical Testing Principles

Use Consistent Testing Methods

• Always use the same nontreponemal test type (RPR or VDRL) from the same laboratory for sequential monitoring 1, 2, 3
• Results from different test types are not directly comparable and should never be used to assess treatment response 1, 2

Understanding Treatment Success

• A fourfold decline in titer (equivalent to a change of two dilutions, such as 1:32 to 1:8) is considered clinically significant evidence of adequate response 1, 2, 3
• Approximately 15-25% of patients treated during primary syphilis may become completely seronegative after 2-3 years 1, 3

The "Serofast" State

A significant proportion of adequately treated patients will remain "serofast":

• Serofast means persistent low-level positive titers (generally <1:8) that remain stable for extended periods, sometimes for life 4, 1
• This does not represent treatment failure 4, 1
• If a patient is serofast, they should be reevaluated for HIV infection 1
• Reinfection should only be suspected if there is at least a fourfold increase above the established serofast baseline 4, 1

Red Flags Indicating Treatment Failure

Suspect treatment failure and consider retreatment if:

• Clinical signs or symptoms persist or recur 4, 2
• Sustained fourfold increase in nontreponemal test titer occurs 4, 2
• Failure to achieve fourfold decline in titers within 6 months for primary/secondary syphilis 2, 6
• Failure to achieve fourfold decline within 12-24 months for latent syphilis 4, 6

Common Pitfalls to Avoid

• Never use treponemal tests (FTA-ABS, TP-PA) to monitor treatment response - these remain positive for life regardless of treatment success 2, 3
• Do not assume persistent low-titer reactivity indicates treatment failure - the serofast state is common and expected 1
• Do not compare titers between different nontreponemal test types (VDRL vs RPR) as they are not interchangeable 1, 2
• Do not delay retesting beyond recommended intervals - early detection of treatment failure is essential for preventing complications and transmission 1, 2