Will a person always test positive for syphilis even if they are treated and cured?

Not necessarily. While serologic tests for syphilis typically remain reactive or positive after successful treatment, the pattern of reactivity changes, and this change can be used to determine if a person has been treated and cured of syphilis.

Serologic tests for syphilis include:

- Nontreponemal tests (such as the Venereal Disease Research Laboratory [VDRL] test and the rapid plasma reagin [RPR] test): These tests detect antibodies produced in response to the infection.

- Treponemal tests (such as the fluorescent treponemal antibody absorption [FTA-ABS] test and the microhemagglutination assay for Treponema pallidum [MHA-TP] test): These tests detect antibodies that specifically recognize the Treponema pallidum bacterium, the causative agent of syphilis.

After successful treatment of syphilis, the titers of nontreponemal antibodies typically decline over time, while the treponemal antibodies may remain positive for life. However, the pattern of reactivity changes:

- During the early stages of treatment, both nontreponemal and treponemal tests may remain positive.

- As treatment continues, the titers of nontreponemal antibodies decline, and the treponemal tests may show a decrease in reactivity or become non-reactive.

- In some cases, the nontreponemal tests may become non-reactive, while the treponemal tests remain positive. This is known as the "serofast" reaction and is considered a sign of successful treatment.

The interpretation of serologic test results for syphilis should be done in conjunction with the patient's clinical history and other diagnostic tests, such as darkfield microscopy or polymerase chain reaction (PCR) tests, to confirm the diagnosis and monitor the response to treatment.