Syphilis is a bacterial infection caused by Treponema pallidum, primarily transmitted through sexual contact. If left untreated, it can lead to severe health complications affecting the brain, heart, and other organ systems. Syphilis is treatable with antibiotics, making early detection through testing a crucial step for both individual health and public well-being. Early identification and treatment can prevent progression to advanced stages and limit further transmission.
When to Consider Testing
Consider syphilis testing if you have engaged in unprotected sex, especially with new or multiple partners, or if a sexual partner has been diagnosed with syphilis or another sexually transmitted infection. Symptoms that may indicate syphilis include a painless sore (chancre) on the genitals, mouth, or rectum, typically 10 to 90 days after exposure. Other signs can include a non-itchy rash on the palms and soles, flu-like symptoms, swollen lymph nodes, or patchy hair loss.
Routine screening is recommended for specific populations. Pregnant individuals should be tested at their first prenatal visit, with additional testing at 28 to 32 weeks of gestation and again at delivery if at high risk or in areas with elevated syphilis rates. Sexually active gay and bisexual men should undergo syphilis testing at least annually, and potentially every three to six months if risk factors are ongoing. People living with HIV should be screened for syphilis at their initial evaluation and at least annually thereafter.
Types of Syphilis Tests
Syphilis testing primarily involves detecting antibodies produced by the immune system in response to the Treponema pallidum bacterium. The diagnostic process uses a two-step approach to ensure accurate results.
Non-treponemal tests, such as RPR and VDRL, are used for initial screening. They identify antibodies produced in response to the bacteria and damaged cells. They can also monitor treatment effectiveness, as antibody levels usually decrease after successful therapy. However, false positive results can occur due to other medical conditions, infections, or pregnancy.
Treponemal tests, including FTA-ABS, TP-PA, and EIA, confirm reactive non-treponemal results. They specifically detect antibodies against Treponema pallidum. Once present, these antibodies usually remain positive for life, even after successful treatment, making treponemal tests unsuitable for monitoring treatment response. For suspected neurosyphilis (syphilis affecting the brain or spinal cord), a VDRL test on cerebrospinal fluid (CSF) may be performed to diagnose neurological involvement.
Where to Get Tested
Several locations offer syphilis testing. Local health departments and community health clinics often offer testing at low or no cost, accommodating walk-ins and appointments. Planned Parenthood centers offer comprehensive sexual health services, including syphilis testing, with income-adjusted fees.
Private healthcare providers, like general practitioners, can also perform syphilis screening via routine blood tests. Some urgent care centers provide discrete, immediate STD testing, sometimes with on-site labs for expedited results. Contact the specific facility beforehand to confirm services, costs, and appointment requirements, as details vary.
Understanding Your Results
A negative syphilis test generally indicates no active infection at the time of testing. Maintaining safe sex practices remains important to prevent future exposures. A positive result signals either a current or past syphilis infection.
If positive, treatment typically involves antibiotics, most commonly penicillin. Dosage and duration depend on the infection stage, following guidelines from health authorities like the CDC. Early-stage syphilis can often be cured with a single dose of penicillin. Individuals diagnosed with syphilis should inform their sexual partners for testing and treatment, which helps curb further transmission. Health departments can provide confidential assistance with partner notification.
Following treatment, repeat blood tests, usually non-treponemal tests, are generally necessary to confirm treatment success. A decrease in antibody levels (titers) indicates a positive response to therapy. Non-treponemal tests may sometimes produce false positive or indeterminate results due to other medical conditions or pregnancy. In such instances, further treponemal testing clarifies the diagnosis, and an indeterminate result may necessitate additional testing or retesting for a definitive conclusion.