Syphilis Testing

Reported cases of new syphilis diagnoses in the United States continue to rise every year. A total of 30,644 cases of primary and secondary (P&S) syphilis were reported in 2017, which represented a 72.7% increase compared with 2013. The rate of reported P&S syphilis cases among men was much higher than that of women, with men accounting for 87.7% of P&S syphilis cases. However, the rate of P&S syphilis among women more than doubled between 2013 and 2017. During 2018, there were 115,045 new diagnoses of syphilis reported.

This guide provides basic information on the STD known as syphilis. Readers will learn about common symptoms of syphilis, including the four stages of the disease. Other information discussed includes testing options and where to get tested. Treatment options for syphilis and how to prevent syphilis exposure are also covered.

The purpose of a syphilis test is to screen for Treponema pallidum, the spirochaete bacterium that causes syphilis, or detect the antibodies your body produces as your immune system tries to fight off the disease. Either would be an indication that you’ve contracted this STD. Syphilis testing may also be used to check how well your treatment is working.

The U.S. Preventive Services Task Force recommends that all pregnant women be tested for syphilis as early in their pregnancy as possible. Even if you don’t have any symptoms, you should also get tested if you’re a sex worker, in prison, engage in male-to-male sex, have unprotected sex with multiple partners, or have a partner who has had unprotected sex with multiple partners. Your doctor may also recommend testing for syphilis if you have HIV or you’re being treated for gonorrhea or another STD.

The most common sample required for testing is blood, either from a finger-stick or vein. Your doctor may also use a tissue or fluid sample from a syphilis sore, called a chancre, or spinal fluid if there’s a chance the infection has already spread to your brain.

Generally, you don’t have to fast or quit taking any medications in preparation for testing. However, your doctor will inform you prior to testing if an exception is required. Either way, it’s important you tell your doctor if you’re currently taking any antibiotics and whether you’re allergic to any antibiotics, especially penicillin. Also, let your doctor know if you’re currently taking blood thinners or if you’re pregnant or think you might be pregnant.

You can get syphilis through direct contact with chancres during oral, vaginal, or anal sex. These sores may be located on the lips, inside the mouth, on or around the penis or vagina, around the anus, and in the rectum or vagina. Syphilis can also be spread by sharing needles used for injecting drugs. Pregnant women with syphilis can also transmit the disease to their unborn child.

On average, the time between first getting syphilis and the onset of symptoms is 21 days. However, this time frame can range between 10 and 90 days. In adults, syphilis symptoms are divided into the four stages of the disease, which include primary, secondary, latent, and late or tertiary syphilis.

There are also several variations of this STD, with many variations occurring due to not seeking treatment. Neurosyphilis usually occurs when the disease is left untreated for 10 to 20 years, leading to a bacterial infection in the brain or spinal cord. There are several types of neurosyphilis, including asymptomatic neurosyphilis, meningeal neurosyphilis, meningovascular neurosyphilis, general paresis, and tabes dorsalis. Ocular syphilis is another form of neurosyphilis that causes disease in the eyes, such as vision loss. Congenital syphilis is the variation of syphilis that a mother can pass to her fetus before birth.

When a person becomes infected with syphilis, they may have very mild symptoms or even no symptoms at all. However, the first sign of syphilis is usually a small, painless sore. Some people may not even notice this sore right away. Other symptoms vary, depending on which of the four stages of syphilis you’re in.

• Primary syphilis is the first stage and occurs approximately three to four weeks after becoming infected with the disease. Generally, the only symptom in this stage is a chancre that’s painless but highly infectious. This sore will likely remain between two and six weeks.
• Secondary syphilis is stage two and often mistaken for other conditions. One common symptom during this stage is a rash that doesn’t itch on the palms of your hands and soles of your feet. Other symptoms may include aching joints, muscle aches, swollen lymph nodes, headaches, fever, weight loss, fatigue, and weight loss. These symptoms go away with or without treatment, but refusing treatment could cause the disease to progress into the next two stages.
• Latent syphilis is stage three and typically called a hidden stage. At this point, any symptoms you previously had during the first two stages disappear, and you won’t have any new or noticeable symptoms. However, the bacteria are still causing havoc inside your body, even if you don’t have any symptoms for years. Eventually, you’ll progress to the final stage.
• Tertiary syphilis is the last stage and the most destructive to your body and your health. The Mayo Clinic reports that about 15% to 30% of people who don’t receive syphilis treatment will end up in this potentially life-threatening stage. Common symptoms of tertiary syphilis include blindness, deafness, destruction of bone and soft tissue, heart disease, memory loss, mental illness, neurological disorders like meningitis or stroke, and neurosyphilis. Most untreated individuals won’t develop tertiary syphilis, but those who do face serious internal organ damage and possibly even death.

The Centers for Disease Control and Prevention (CDC) also notes that 80% of pregnant women with untreated syphilis they acquired during the four years before giving birth, passed the infection on to their fetus. Furthermore, up to 40% of these cases resulted in stillbirth or death of the infant.

If you think you may have been exposed to or have syphilis, visit your doctor as soon as possible. In a doctor’s office or other health care facility, testing for syphilis is often done by using a blood sample collected either from a finger-stick or a vein. If you currently have a chancre, your doctor may also take a sample of fluid or tissue from the sore to test for syphilis bacteria.

Testing for syphilis is a two-step process that includes completing a nontreponemal antibody screening test, followed by a treponemal antibody detection test to confirm the results from the initial test. However, these tests can be done in the reverse order with a second treponemal test performed if test results differ.

Tests used to screen for syphilis include:

• Venereal disease research laboratory (VDRL) tests check blood or spinal fluids for antibodies produced in people with syphilis.
• Rapid plasma reagin (RPR) tests also look for syphilis antibodies but only with a blood sample.
• Rapid immunochromatographic tests also check for antibodies directly linked to syphilis through a blood test.

Tests used to confirm syphilis infection:

• Enzyme immunoassay (EIA) tests check for syphilis in the blood.
• Fluorescent treponemal antibody absorption (FTA-ABS) tests detect antibodies, except during the first three to four weeks following exposure, and may utilize a blood sample or spinal fluid sample.
• Treponema pallidum particle agglutination assay (TPPA) tests check for syphilis antibodies in blood only.
• Darkfield microscopy testing uses a special microscope to look for the syphilis germ in a fluid or tissue sample from an open chancre in the early stages of the disease.
• Microhemagglutination assay (MHA-TP) tests are used to confirm infection in the early stages of the disease.

One test from the screening set and one from the confirming set of syphilis testing options must be used in conjunction to confirm infection of the STD positively. If your doctor suspects you may have nervous system problems caused by tertiary syphilis, a lumbar puncture, also called a spinal tap, may be ordered to collect spinal fluid for testing.

You can get tested for syphilis at your doctor’s office, a community health clinic, the health department, an STD testing facility, or a Planned Parenthood health center. However, many people choose to use an at-home syphilis test kit, which is often more affordable and confidential. These tests are simple to use and come with everything you need to obtain a sample. Most at-home kits that specifically test for syphilis require a blood sample that you mail to a lab for testing and then wait for the physician-reviewed results, which you should receive in a few days.

Syphilis is treatable, and even curable, with antibiotics. It’s important you consult your doctor as soon as you think you’ve been exposed. The longer you go without receiving treatment, the more the syphilis-causing bacteria can spread through your body and cause serious complications, especially in your organs.

Penicillin remains the preferred treatment for syphilis at all stages; however, different types and potency levels of penicillin are used, depending on what stage you’re in. Primary and secondary syphilis are usually effectively treated with a single dose of penicillin injected directly into the muscle. If you’ve had the STD for a while and it has progressed, you may need multiple doses of the same type of penicillin at a higher potency level in weekly intervals. If you have neurosyphilis, you’ll receive much higher daily doses of a different type of penicillin, which is administered intravenously or potentially through continuous infusion.

Selection of the appropriate penicillin preparation is important to properly treat and cure syphilis, which is why it’s important to see your doctor for an appropriate treatment plan. While the penicillin will kill the bacteria that causes syphilis, any damage that has already occurred in your organs will likely be permanent. Further treatment to ease your pain and discomfort may be prescribed. If you’re allergic to penicillin, you may be treated with an alternate antibiotic, followed by close laboratory testing and clinical review to ensure an appropriate response.

For most home testing kits specifically for syphilis, all you need is a small blood sample collected from a finger-stick. These kits come with detailed directions and everything you need to collect your sample, including a small lancet to prick your fingertip. Once you’ve obtained your sample, immediately return it to the company’s lab in the pre-addressed, postage-paid envelope. Results are usually available within a few business days, typically between two and five days.

Many pharmacies regularly carry at-home syphilis kits or can order one for you. However, if you prefer something more discreet, you can order a kit online from numerous reputable companies. Once received, you take the test in the privacy of your own home, ship the sample back, and confidentially receive your results.

If your test comes back positive for syphilis antibodies, you might have syphilis, but you need further testing to be sure. Talk to your doctor, who will order a more specific test to confirm your positive result. Numerous things can cause a false-positive, including HIV, certain types of pneumonia, tuberculosis, Lyme disease, lupus, malaria, and IV drug use.

Syphilis can be cured with the right antibiotics from your doctor, but treatment won’t undo the damage already done to your tissue and organs. Having syphilis once doesn’t provide immunity. Even after successfully curing syphilis with treatment, you can still get it again. Once you’ve been diagnosed with syphilis, you must notify your previous sex partners to let them know they need to be tested.

If you’re using an at-home test kit, you must mail it in, which could take a few days depending on where the package is going. Then, the company must test it. Once they receive your sample, results usually take anywhere between two and five days. When getting tested in your doctor’s office or other health care facility, it still usually takes a few days to receive your results.

• The Centers for Disease Control and Prevention provides an in-depth look at what causes syphilis, how it’s spread, and what options you have for treatment and care.
• For a look at acquired syphilis and related disorders, including standard and investigational therapies, check out the National Association of Rare Disorders.
• The American Sexual Health Association manages a site, iwannaknow.org, that speaks primarily to young adults and teens about the importance of preventing the spread of syphilis.

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