Syphilis was supposed to be a relic of the past — a disease conquered by penicillin in the mid-twentieth century and steadily declining ever since. That narrative is no longer true. Across Europe, the Americas, and beyond, syphilis cases are climbing at rates not seen in decades. In the European Union and European Economic Area, reported syphilis cases reached approximately 41,000 in 2023 — double the number recorded in 2014. Chlamydia and gonorrhea are surging alongside it.

The United States mirrors this trajectory. CDC surveillance data show syphilis cases have been rising sharply since 2017, with congenital syphilis — the form passed from mother to child during pregnancy — reaching levels not seen since the early 1990s. In several major cities, the increase has been dramatic enough to prompt public health emergencies.

This is not a story about a rare tropical disease or an obscure laboratory finding. Syphilis is a common, easily transmitted infection caused by a spiral-shaped bacterium called Treponema pallidum. Left untreated, it progresses through increasingly dangerous stages and can ultimately damage the brain, heart, and other organs. But detected early, it remains one of the most treatable sexually transmitted infections (STIs) in existence — a single injection of penicillin can cure it.

This article covers what syphilis is, how it spreads, what its symptoms look like at each stage, why cases are surging, how to get tested, and — most importantly — how to protect yourself.

What Is Syphilis?

Syphilis is a bacterial infection caused by Treponema pallidum, a corkscrew-shaped organism (spirochete) that can invade virtually any organ in the body. It is primarily transmitted through sexual contact — vaginal, anal, and oral sex — but can also be passed from mother to child during pregnancy or birth (congenital syphilis), and very rarely through blood transfusion or direct contact with an active sore.

The bacterium enters the body through mucous membranes or tiny breaks in the skin. Once inside, it spreads through the bloodstream, which is why syphilis is called a systemic infection — it does not stay confined to one area. Without treatment, the disease progresses through four distinct stages, each with different symptoms and levels of infectiousness.

Syphilis has been called "the great imitator" because its symptoms can mimic dozens of other conditions — from allergic reactions to autoimmune diseases. This makes clinical diagnosis challenging and underscores why laboratory testing is essential.

The Four Stages of Syphilis

Understanding the stages of syphilis is critical because the symptoms, infectiousness, and treatment implications differ dramatically at each phase.

Primary Syphilis

The first sign of syphilis is typically a painless sore called a chancre (pronounced "shanker"). It appears at the site where the bacterium entered the body — usually the genitals, anus, rectum, or mouth — typically 10 to 90 days after exposure, with an average of about three weeks.

Key characteristics of the chancre:

  • Painless — This is the most deceptive feature. Because it does not hurt, many people never notice it, especially if it is inside the vagina, rectum, or mouth.
  • Round and firm — It has a clean, raised edge and a smooth base.
  • Usually single — Though multiple chancres can occur, especially in people with HIV.
  • Highly infectious — The sore is teeming with Treponema pallidum bacteria. Direct contact with a chancre during sex is the primary route of transmission.

Even without treatment, the chancre heals on its own within 3–6 weeks. This self-resolution is dangerous because it creates the false impression that whatever was wrong has resolved — when in fact the bacterium has simply moved deeper into the body.

Secondary Syphilis

If primary syphilis goes untreated, the disease progresses to the secondary stage, typically 4–10 weeks after the chancre first appears. Secondary syphilis is a systemic infection — the bacterium has now spread throughout the body — and its symptoms are widespread.

The hallmark symptom is a rash:

  • It often starts on the trunk and then spreads to the entire body, including the palms of the hands and soles of the feet — a distribution that is unusual for most rashes and should always raise clinical suspicion.
  • The rash is typically not itchy, which is another reason people may dismiss it.
  • It can appear as rough, reddish-brown spots, or as flat, velvety patches in moist areas (called condylomata lata), or as small round lesions.

Other symptoms of secondary syphilis include:

  • Fever, fatigue, and malaise — Feeling generally unwell, as with any systemic infection
  • Swollen lymph nodes — Often painless, in multiple locations
  • Sore throat and patchy hair loss — The "moth-eaten" pattern of alopecia is distinctive
  • Headaches and muscle aches — Sometimes severe enough to mimic meningitis
  • Weight loss — Unintentional and sometimes significant

Secondary syphilis is the most infectious stage. The rash lesions, mucosal patches, and condylomata lata all contain high concentrations of bacteria. Like the chancre, these symptoms will eventually resolve on their own — but the infection persists.

Latent Syphilis

After the symptoms of secondary syphilis disappear, the infection enters a latent (hidden) phase. There are no visible symptoms, but the bacterium remains in the body. Latent syphilis is divided into two categories based on the BASHH 2024 guidelines and other clinical frameworks:

  • Early latent — Less than one to two years since infection (the exact cutoff varies by guideline). The person can still transmit syphilis to sexual partners, and pregnant women can transmit it to their unborn child.
  • Late latent — More than one to two years since infection, or unknown duration. Transmission to sexual partners is less likely, but vertical transmission (mother to child) remains possible.

Latent syphilis can last for years — even decades. About one-quarter to one-third of people with untreated latent syphilis will eventually progress to tertiary syphilis.

Tertiary Syphilis

Tertiary syphilis is the most destructive stage and can develop 3 to 15 years or more after the initial infection. It affects multiple organ systems and can be fatal. The three main forms are:

  • Cardiovascular syphilis — Inflammation of the aorta (the body's main artery), which can lead to aortic aneurysm, aortic valve insufficiency, and heart failure. This was historically a major cause of death from syphilis.
  • Neurosyphilis — Infection of the brain and spinal cord, causing symptoms ranging from headaches and difficulty concentrating to dementia, personality changes, paralysis, and blindness. Neurosyphilis can actually occur at any stage, but it is most devastating when it develops years after the initial infection.
  • Gummatous syphilis — Formation of destructive, granulomatous lesions (gummas) in the skin, bones, liver, and other organs. These soft, tumor-like growths can cause significant tissue damage.

The good news: tertiary syphilis is now relatively rare in countries with accessible healthcare, because most cases are detected and treated before reaching this stage. But it has not disappeared entirely — and in populations with limited access to testing and treatment, it remains a genuine threat.

Congenital Syphilis: The Crisis Within the Crisis

Perhaps the most alarming aspect of the syphilis resurgence is the sharp increase in congenital syphilis — the transmission of the infection from a pregnant person to their developing fetus. Congenital syphilis is entirely preventable with adequate prenatal screening and treatment, which makes its resurgence a failure of public health systems rather than a failure of medicine.

Syphilis can cross the placenta at any stage of pregnancy, but the risk is highest in primary and secondary stages. Untreated syphilis during pregnancy can lead to:

  • Miscarriage and stillbirth — Syphilis is one of the leading infectious causes of stillbirth worldwide
  • Premature birth and low birth weight
  • Neonatal death — Within the first month of life
  • Congenital abnormalities — Including bone deformities, neurological damage, liver and spleen enlargement, anemia, and the characteristic "saddle nose" deformity
  • Late manifestations — Dental abnormalities (Hutchinson's teeth), hearing loss, and eye problems that may not appear until years later

The World Health Organization has made elimination of mother-to-child transmission of syphilis a global public health priority. The intervention is straightforward: screen all pregnant people for syphilis early in pregnancy, and treat those who test positive with penicillin — the same inexpensive, widely available antibiotic that has been used for this purpose since the 1940s. When treatment is administered early enough in pregnancy, it cures the mother and prevents infection in the fetus in the vast majority of cases.

Why Is Syphilis Coming Back?

The resurgence of syphilis is a complex phenomenon with no single explanation. Researchers and public health authorities point to several converging factors.

Declining Condom Use

Multiple studies indicate that consistent condom use has been declining, particularly among younger populations. A large international survey conducted with participation from the World Health Organization found that adolescents are using condoms less frequently than a decade ago. The WHO attributes this in part to gaps in comprehensive sex education.

Several countries have responded with programs to increase condom access. France began providing free condoms to people aged 18–25 at pharmacies in 2023, and Spain has considered similar measures.

The Success of HIV Treatment Changing Risk Perception

The widespread availability of HIV pre-exposure prophylaxis (PrEP) and effective antiretroviral therapy has transformed HIV from a death sentence into a manageable chronic condition. This is an extraordinary public health achievement. However, some researchers have documented a phenomenon called "risk compensation" — when the perceived reduction in HIV risk leads some people to reduce or abandon condom use, inadvertently increasing their exposure to other STIs like syphilis, gonorrhea, and chlamydia.

It is important to emphasize: PrEP is a life-saving tool, and the solution is not less PrEP but better STI screening and education alongside PrEP programs.

Chemsex and Substance Use

Chemsex — sexual activity under the influence of specific psychoactive substances such as methamphetamine, mephedrone, GHB/GBL, and others — has been identified as a risk factor for STI acquisition. Under the influence of these substances, people are less likely to use condoms, more likely to have multiple partners in a single session, and more likely to engage in sexual practices that carry higher transmission risk. Chemsex is particularly prevalent in certain men-who-have-sex-with-men (MSM) communities, though it is not limited to any one population.

Erosion of Public Health Infrastructure

In many countries, sexual health clinics have faced budget cuts, reduced staffing, and clinic closures. The COVID-19 pandemic exacerbated these problems: routine STI screening was disrupted, clinic hours were reduced, and resources were diverted to pandemic response. While STI transmission may have temporarily slowed during lockdowns, the subsequent rebound has been dramatic — and the weakened infrastructure has struggled to respond.

Dating Apps and Sexual Networks

The widespread adoption of dating and hookup apps has changed sexual network dynamics. These platforms can facilitate rapid partner acquisition, which increases the potential for STI transmission within interconnected networks. This is not a moral judgment — it is an epidemiological observation. The same technology that increases connection opportunities can also be leveraged for public health interventions, such as in-app testing reminders and partner notification features.

How Syphilis Spreads — and How It Does Not

Understanding transmission routes is essential for effective prevention.

How Syphilis IS Transmitted

  • Vaginal, anal, and oral sex — Any sexual contact involving mucous membranes or skin that comes into contact with a syphilitic lesion (chancre, rash lesion, or condylomata lata). Anal sex carries a particularly high risk because the rectal mucosa is thin and susceptible to micro-tears.
  • Direct contact with an active sore — Including touching a chancre or secondary-stage lesion, then touching your own mucous membrane or broken skin. This route is uncommon but documented in clinical literature.
  • Mother to child — During pregnancy (transplacental) or during birth through contact with active lesions.
  • Blood transfusion — Extremely rare in countries with routine blood screening, but theoretically possible because the bacterium can circulate in the bloodstream.
  • Shared sex toys — If used sequentially without cleaning or covering with a new condom between partners.

How Syphilis Is NOT Transmitted

Syphilis cannot be transmitted through:

  • Toilet seats, doorknobs, or shared clothing
  • Swimming pools or hot tubs
  • Sharing utensils, cups, or food
  • Hugging, shaking hands, or casual physical contact
  • Coughing or sneezing

Treponema pallidum is a fragile organism that cannot survive outside the human body for any meaningful period. It requires warm, moist conditions to remain viable.

Getting Tested: What You Need to Know

Syphilis testing is straightforward, widely available, and — because syphilis can be asymptomatic for long periods — absolutely essential for anyone who is sexually active.

Who Should Be Tested

General screening recommendations from major health organizations, including the CDC and NHS, include:

  • All pregnant people — At the first prenatal visit, and again in the third trimester and at delivery if at increased risk
  • Men who have sex with men (MSM) — At least annually, and every 3–6 months for those with multiple partners or other risk factors
  • People living with HIV — At least annually
  • Anyone with a new sexual partner — Before initiating unprotected sexual contact
  • Anyone diagnosed with another STI — Co-infection is common
  • Anyone with symptoms — Any unexplained sore, rash, or systemic illness in a sexually active person warrants testing
  • Anyone who has had a partner diagnosed with syphilis — Regardless of symptoms

Types of Syphilis Tests

Syphilis testing involves blood tests that detect antibodies produced by the immune system in response to the infection. There are two categories:

Non-treponemal tests (RPR, VDRL):

  • Detect antibodies that are produced in response to tissue damage caused by the infection, but are not specific to Treponema pallidum
  • Used for screening and monitoring treatment response
  • Results are reported as titers (e.g., 1:8, 1:32) — higher titers generally indicate more active infection
  • Can produce false positives in certain conditions (pregnancy, autoimmune diseases, some viral infections)

Treponemal tests (FTA-ABS, TP-PA, EIA/CIA):

  • Detect antibodies specifically directed against Treponema pallidum
  • Used to confirm a positive screening test
  • Once positive, treponemal tests usually remain positive for life, even after successful treatment — so they cannot be used to monitor treatment response

Most laboratories use a "reverse algorithm" approach: screening with a treponemal test first (which can be automated and is highly sensitive), then confirming with a non-treponemal test and determining the titer.

The Window Period

After exposure, it takes time for the body to produce detectable antibodies. This "window period" for syphilis is typically 1–4 weeks after the chancre appears (or approximately 3–6 weeks after exposure). Testing too early can produce a false negative. If you have a known exposure, your healthcare provider may recommend initial testing followed by repeat testing 4–6 weeks later.

Rapid Point-of-Care Tests

Rapid syphilis tests are available in many clinical settings and can provide results in 15–20 minutes from a finger-prick blood sample. These are treponemal tests — they detect antibodies to the bacterium but cannot distinguish between current and past infections. A positive rapid test should always be confirmed with laboratory testing.

Treatment: Still Remarkably Effective

One of the most important things to know about syphilis is that it remains highly treatable. The cornerstone of treatment has not changed since the 1940s: penicillin.

Standard Treatment by Stage

  • Primary, secondary, and early latent syphilis — A single intramuscular injection of benzathine penicillin G (2.4 million units). That is it. One shot can cure an infection that, left untreated, would progress for years.
  • Late latent syphilis or syphilis of unknown duration — Three injections of benzathine penicillin G, given at weekly intervals (2.4 million units per dose).
  • Neurosyphilis — Intravenous aqueous crystalline penicillin G, administered every 4 hours for 10–14 days. This requires hospitalization or an outpatient infusion setup.

For people with a documented penicillin allergy, alternatives include doxycycline (100 mg twice daily for 14–28 days depending on stage). However, for pregnant people with syphilis, penicillin is the only proven treatment — penicillin allergy desensitization is recommended rather than substituting an alternative antibiotic.

The Jarisch-Herxheimer Reaction

Within the first 24 hours after treatment, some people experience a temporary worsening of symptoms — fever, chills, headache, muscle pain, and a flare of skin lesions. This is called the Jarisch-Herxheimer reaction and occurs because the rapid killing of large numbers of bacteria releases inflammatory substances. It is not an allergic reaction to penicillin. It is uncomfortable but self-limiting and typically resolves within 24 hours. Your doctor should warn you about it in advance so you do not mistake it for a treatment failure or allergic response.

Follow-Up After Treatment

After treatment, your healthcare provider will monitor your non-treponemal test titers (RPR or VDRL) at regular intervals — typically at 3, 6, 12, and 24 months. A successful treatment response is indicated by a fourfold decline in titer (for example, from 1:32 to 1:8). If titers do not decline as expected, retreatment may be necessary.

Partner Notification

If you are diagnosed with syphilis, your sexual partners need to be notified so they can be tested and treated. Depending on the stage of your infection, your healthcare provider or local health department may help with anonymous partner notification — a process in which your partners are informed of their potential exposure without your identity being revealed.

Syphilis and HIV: A Dangerous Synergy

Syphilis and HIV have a bidirectional relationship that amplifies the danger of both infections.

Having syphilis — particularly an active chancre or mucosal lesion — significantly increases vulnerability to HIV. The open sore provides a direct portal of entry for the virus, and the local immune response to syphilis recruits the very immune cells (CD4+ T cells) that HIV targets for infection. Studies estimate that having syphilis increases the risk of acquiring HIV by 2–5 times.

Conversely, HIV infection can alter the course of syphilis. People living with HIV may experience more aggressive syphilis progression, atypical presentations, and a higher rate of neurosyphilis. Treatment response can also be different — some guidelines recommend more intensive follow-up for HIV-positive individuals treated for syphilis.

This is why comprehensive STI screening — not just HIV testing alone — is so important for sexually active individuals, particularly those at higher risk.

Prevention: A Multilayered Approach

There is no vaccine for syphilis (though research is ongoing). Prevention relies on a combination of behavioral strategies, biomedical tools, and regular screening.

Barrier Methods

Condoms remain the most accessible and broadly effective tool for reducing STI transmission. When used correctly and consistently, external (male) and internal (female) condoms significantly reduce the risk of syphilis transmission during vaginal and anal sex. For oral sex, dental dams or condoms provide a barrier. The CDC emphasizes that while condoms do not eliminate syphilis risk entirely — because the chancre may be in a location not covered by the condom — they substantially reduce it.

Key points about condoms and syphilis:

  • Condoms reduce but do not eliminate transmission risk (the chancre can appear on areas outside the condom's coverage)
  • Use a new condom for each act of vaginal, anal, or oral sex
  • Water-based or silicone-based lubricant reduces the chance of condom breakage
  • Condoms also protect against HIV, gonorrhea, chlamydia, and other STIs simultaneously

Doxycycline Post-Exposure Prophylaxis (Doxy-PEP)

One of the most significant developments in STI prevention in recent years is the use of doxycycline as post-exposure prophylaxis — commonly called "doxy-PEP." This involves taking a single 200 mg dose of doxycycline within 72 hours after condomless sex.

Clinical trials have shown that doxy-PEP reduces the incidence of syphilis by approximately 70–80% and chlamydia by about 70–90%. The evidence is strongest in men who have sex with men and transgender women. In 2024, the CDC issued guidance supporting doxy-PEP for these populations, and the IUSTI Europe guidelines board has also issued a position statement.

Important caveats:

  • Doxy-PEP is a prescription medication — discuss it with your healthcare provider
  • It does not protect against HIV (PrEP is needed for that)
  • Its effectiveness against gonorrhea is limited, likely due to widespread doxycycline resistance in Neisseria gonorrhoeae
  • Long-term impacts on antimicrobial resistance are still being studied
  • It is not a replacement for condoms — it is an additional layer of protection

HIV Pre-Exposure Prophylaxis (PrEP)

While PrEP does not prevent syphilis, it is relevant to this discussion for two reasons. First, people taking PrEP are typically enrolled in regular STI screening programs (usually every 3 months), which means syphilis is more likely to be detected and treated early. Second, PrEP eliminates the fear of HIV, which can reduce a major barrier to getting tested for all STIs.

Post-Exposure Prophylaxis (PEP) for HIV

If you have had a potential exposure to HIV (through condomless sex with a partner of unknown status, sexual assault, or needle sharing), post-exposure prophylaxis should be started within 72 hours. PEP involves taking antiretroviral medications for 28 days. While PEP does not prevent syphilis, a PEP consultation is an opportunity for comprehensive STI screening and treatment.

Vaccination Against Other STIs

While there is no syphilis vaccine, vaccines exist for two other sexually transmitted pathogens:

  • HPV vaccine — Protects against human papillomavirus, which causes genital warts, cervical cancer, and several other cancers. Recommended for all people through age 26, with catch-up vaccination available through age 45.
  • Hepatitis B vaccine — Protects against a virus transmitted through sexual contact and blood. Part of routine childhood immunization in most countries, but adults who were not vaccinated should consider it, especially if sexually active with multiple partners.
  • Mpox (monkeypox) vaccine — Available for individuals at higher risk, particularly MSM with multiple partners. WHO recommendations outline eligibility criteria.

Getting vaccinated against preventable STIs while also practicing syphilis prevention creates a more comprehensive shield against sexually transmitted disease overall.

Talking to Partners About STI Testing

One of the most effective — and most dreaded — prevention strategies is simply having honest conversations with sexual partners about STI testing and status. Research consistently shows that open communication about sexual health is associated with increased condom use and higher rates of testing.

This does not need to be a dramatic confrontation. Planned Parenthood's guidance on the topic suggests framing it as a mutual health decision rather than an accusation:

  • Normalize it: "I get tested regularly — it is just part of taking care of my health. When was your last test?"
  • Make it mutual: "Why don't we both get tested before we stop using condoms? It would put both our minds at ease."
  • Be direct without blame: "I think it is important for both of us to know our status. Can we talk about getting tested?"
  • Acknowledge the awkwardness: "I know this is an uncomfortable conversation, but I care about both of our health."

If a partner refuses to discuss testing or dismisses your concerns, that itself is important information. Your sexual health is not negotiable.

Syphilis and Other Common STIs: What Else to Watch For

Syphilis rarely travels alone. When STI rates rise in a population, they tend to rise together. If you are getting tested for syphilis, it makes sense to screen for other common STIs as well.

Gonorrhea

Caused by Neisseria gonorrhoeae, gonorrhea infects the urethra, cervix, rectum, and throat. It can be asymptomatic, especially in women and in rectal infections. Untreated, it causes pelvic inflammatory disease, infertility, and increases HIV transmission risk. Gonorrhea is becoming increasingly difficult to treat due to antimicrobial resistance — some strains are now resistant to nearly all available antibiotics, making it a growing global health concern.

Key points: screen at all exposed anatomical sites (urine alone misses pharyngeal and rectal infections), and always test for gonorrhea alongside syphilis and chlamydia.

Chlamydia

The most commonly reported bacterial STI worldwide, chlamydia is caused by Chlamydia trachomatis. It is frequently asymptomatic — up to 75% of women and 50% of men have no symptoms. Untreated chlamydia can cause pelvic inflammatory disease, ectopic pregnancy, and infertility. Testing is simple (urine sample or swab) and treatment is straightforward (azithromycin or doxycycline).

HIV

Human immunodeficiency virus attacks the immune system and, without treatment, leads to AIDS. Modern antiretroviral therapy means that people living with HIV who achieve an undetectable viral load have effectively zero risk of transmitting the virus to sexual partners (U=U: undetectable equals untransmittable). However, testing is the critical first step — you cannot treat what you do not know about.

Hepatitis B

Transmitted through blood and body fluids, hepatitis B can become a chronic infection causing liver cirrhosis and liver cancer. Unlike most STIs, hepatitis B is vaccine-preventable. If you were not vaccinated as a child, consider getting vaccinated now — especially if you are sexually active with multiple partners.

A comprehensive STI panel — covering syphilis, HIV, gonorrhea, chlamydia, and hepatitis B at minimum — provides a much more complete picture than testing for any single infection.

Special Populations and Considerations

Men Who Have Sex with Men (MSM)

MSM are disproportionately affected by the syphilis resurgence. In the US and Europe, MSM account for the majority of reported primary and secondary syphilis cases. This is driven by biological factors (rectal mucosa is more susceptible to infection), network effects (interconnected sexual networks facilitate rapid spread), and structural factors (stigma can delay testing). The CDC recommends that sexually active MSM be screened for syphilis at least annually, and every 3–6 months for those with multiple partners or other risk factors.

Pregnant People

Universal syphilis screening in pregnancy is one of the most cost-effective public health interventions in existence. Despite this, many countries still have gaps in prenatal screening coverage, contributing to the resurgence of congenital syphilis. If you are pregnant or planning pregnancy, ensure syphilis screening is part of your prenatal care. Repeat screening in the third trimester is recommended if you have risk factors for new acquisition.

People Living with HIV

As discussed above, HIV and syphilis interact in ways that make both infections more dangerous. People living with HIV should be screened for syphilis at every clinical visit or at least annually. Co-infection requires careful management and sometimes modified treatment protocols.

Adolescents and Young Adults

Young people (ages 15–24) account for a disproportionate share of new STI cases. This age group may face additional barriers to testing, including lack of knowledge about STI symptoms, concern about confidentiality, cost of testing, and discomfort discussing sexual health with healthcare providers. Many countries offer free and confidential STI testing services specifically designed for young people.

Myths and Misconceptions About Syphilis

Misinformation about syphilis is widespread and can directly undermine prevention efforts. Here are some of the most dangerous myths.

"Syphilis only affects certain groups." While MSM are currently disproportionately affected, syphilis does not discriminate. Heterosexual transmission is increasing in many countries, and congenital syphilis — by definition — affects infants born to people of any sexual orientation. Anyone who is sexually active can contract syphilis.

"You would know if you had syphilis." This is perhaps the most dangerous myth. Primary syphilis produces a painless sore that can be hidden inside the vagina, rectum, or mouth. Secondary syphilis produces a rash that may be subtle and non-itchy. Latent syphilis produces no symptoms at all. The only way to know is to get tested.

"Syphilis went away." Syphilis never disappeared. Rates declined dramatically after the introduction of penicillin and again during the height of the HIV/AIDS epidemic (when safer sex practices became widespread), but the bacterium has been continuously circulating in human populations for centuries.

"You cannot get syphilis from oral sex." Oral sex is a recognized route of syphilis transmission. Chancres can develop in the mouth, on the lips, or in the throat. The risk is lower than for anal sex but is not negligible.

"Once treated, you are immune." Curing syphilis does not create lasting immunity. You can be reinfected as many times as you are re-exposed. Each new infection carries the same risks as the first and requires a new course of treatment.

"Washing after sex prevents syphilis." There is no evidence that washing, douching, or using antiseptics after sex prevents syphilis or other STIs. The bacterium penetrates mucous membranes rapidly, and no amount of post-coital hygiene can reverse that. This myth is explicitly not included in any evidence-based clinical guidelines.

The Antibiotic Resistance Question

Unlike gonorrhea, which has developed resistance to nearly every antibiotic class ever used to treat it, syphilis has remained remarkably susceptible to penicillin. After more than 80 years of use, there are no confirmed cases of penicillin-resistant Treponema pallidum.

However, resistance to macrolide antibiotics (particularly azithromycin, which was sometimes used as an alternative to penicillin) has been documented in multiple studies and is now widespread in many regions. This is why penicillin — not azithromycin — remains the first-line treatment.

The emergence of azithromycin resistance is a cautionary tale about the importance of antibiotic stewardship. While penicillin resistance in syphilis has not yet appeared, researchers continue to monitor for it, and the possibility cannot be ruled out indefinitely. This is another reason why prevention — reducing the need for treatment in the first place — is so important.

Living with a Syphilis Diagnosis: Practical Considerations

Receiving a syphilis diagnosis can be distressing, but it is important to keep several things in perspective.

It is treatable. In its early stages, syphilis is cured with a single injection. Even in later stages, it responds to antibiotics. Very few infectious diseases are this straightforward to treat.

It is more common than you think. You are not alone. Hundreds of thousands of people are diagnosed with syphilis each year in Europe and the United States alone. The stigma surrounding STIs is disproportionate to their medical reality.

Partner notification matters. Informing your sexual partners is not just ethically important — it is a critical public health measure that prevents ongoing transmission. Many health departments offer confidential or anonymous notification services. The CDC provides guidance on how to approach these conversations.

Follow-up is essential. Do not skip your post-treatment blood tests. Monitoring your RPR/VDRL titers is the only way to confirm that treatment was successful and to detect reinfection early.

Reinfection is possible. After treatment, you are not immune. If your risk factors have not changed, your risk of reinfection has not changed either. Consider what prevention strategies you can implement to reduce your future risk.

What Gonorrhea's Resistance Crisis Tells Us About the Future

Gonorrhea — another STI that is surging alongside syphilis — offers a sobering preview of what happens when an STI develops antimicrobial resistance. Neisseria gonorrhoeae has progressively developed resistance to sulfonamides, penicillin, tetracyclines, fluoroquinolones, and now shows decreasing susceptibility to ceftriaxone, the last remaining first-line injectable treatment.

The Australian STI guidelines now recommend dual antibiotic therapy for gonorrhea as standard practice. Recent surveillance data published in Sexually Transmitted Infections have documented emerging resistance patterns in multiple geographic regions, raising alarm about the possibility of untreatable gonorrhea.

Why does this matter for syphilis? Because the same behavioral and structural factors driving syphilis also drive gonorrhea. Co-infection is common. And while syphilis remains penicillin-sensitive today, the gonorrhea experience demonstrates that we cannot take continued antibiotic effectiveness for granted. Prevention — through condoms, doxy-PEP where appropriate, regular screening, and prompt treatment — is the only durable strategy.

How Regular Screening Fits Into Your Health Routine

STI screening should not be an emergency-only activity. For sexually active adults, it should be as routine as a dental cleaning or an annual physical — a regular maintenance task that protects your health and your partners' health.

How often you should be tested depends on your individual risk profile:

  • Every 3 months: MSM with multiple partners, people using PrEP (screening is usually built into PrEP protocols), people with a recent STI diagnosis, people who engage in chemsex
  • Every 6–12 months: Sexually active adults under 25, anyone with a new partner, anyone with more than one partner in the past year
  • At each prenatal visit: All pregnant people (with repeat screening in the third trimester if at risk)
  • When symptoms appear: Any unexplained genital sore, rash, discharge, or pain
  • After a known exposure: Even in the absence of symptoms

The Australian government's STI testing guidance provides a useful decision framework that can be adapted to any country's healthcare system.

Using WatchMyHealth's physician visit tracker, you can schedule reminders for regular STI screening appointments, log your test results over time, and maintain a complete record of your sexual health screening history. This kind of tracking is especially valuable if you see different healthcare providers — having a centralized record ensures nothing falls through the cracks.

A Note on Stigma

Stigma is one of the most significant barriers to STI prevention and treatment. Fear of judgment prevents people from getting tested, disclosing their status to partners, and seeking treatment promptly. This delay in care does not just harm the individual — it allows the infection to spread to others.

Syphilis, like all STIs, is an infection — not a moral failing. It can affect anyone who is sexually active, regardless of the number of partners they have, their relationship status, their gender identity, or their sexual orientation. Framing STIs as punishment for "risky behavior" is not only scientifically inaccurate — it actively undermines public health efforts.

If you are diagnosed with syphilis or any other STI, you deserve compassionate, nonjudgmental healthcare. If your current provider does not offer that, seek a sexual health clinic or STI-specialized service where the staff are trained specifically in this area.

And if someone discloses an STI diagnosis to you — whether a partner, friend, or family member — respond with support rather than shame. They are doing the right thing by telling you.

Frequently Asked Questions

Can syphilis be cured completely? Yes. When detected and treated with appropriate antibiotics (usually penicillin), syphilis is completely curable. Early-stage syphilis is cured with a single injection. However, any organ damage that occurred before treatment (particularly in tertiary syphilis) may be irreversible.

How long after exposure should I get tested? The window period for syphilis testing is approximately 3–6 weeks after exposure. If you have a known exposure, get an initial baseline test and then a follow-up test 4–6 weeks later.

Can I get syphilis more than once? Yes. Having syphilis does not create immunity. You can be reinfected every time you are exposed. Each new infection requires treatment.

Is syphilis only transmitted during sex? Sexual contact is by far the primary route. Syphilis can also be transmitted from mother to child during pregnancy (congenital syphilis) and very rarely through blood transfusion. It is not transmitted through casual contact, sharing utensils, or toilet seats.

Can syphilis cause permanent damage? If left untreated for years, tertiary syphilis can cause irreversible damage to the heart, brain, nerves, bones, and other organs. Congenital syphilis can cause permanent disability in affected children. This is why early detection and treatment are so critical.

Does having syphilis mean I also have HIV? No. Syphilis and HIV are caused by different pathogens and are separate infections. However, having syphilis increases your risk of acquiring HIV, and co-infection is common in certain populations. Getting tested for both — and for other STIs — is always recommended.

My treponemal test is still positive after treatment — does that mean I still have syphilis? Not necessarily. Treponemal tests often remain positive for life after infection, even after successful treatment. Treatment success is monitored through non-treponemal tests (RPR/VDRL), which should show a declining titer.

Should I avoid sex during treatment? Yes. Abstain from sexual contact until your treatment is complete, your healthcare provider has confirmed the infection is resolving (typically based on follow-up testing and symptom resolution), and any partners who need treatment have also been treated.

Is there a syphilis vaccine? Not yet. Research into a syphilis vaccine is ongoing, but no candidate has reached clinical trials as of 2026. Prevention currently relies on behavioral strategies, barrier methods, doxy-PEP, and regular screening.

Key Takeaways

Syphilis is back — and understanding it is the first step toward protecting yourself.

  • Syphilis cases have surged globally, doubling in Europe since 2014 and rising sharply in the United States. Congenital syphilis has reached levels not seen in decades.
  • It progresses through four stages — primary (painless sore), secondary (systemic rash and symptoms), latent (no symptoms), and tertiary (organ damage). Each stage except tertiary is highly infectious.
  • Syphilis is treatable — Early-stage syphilis is cured with a single penicillin injection. Even later stages respond to antibiotics. But damage from tertiary syphilis may be irreversible.
  • Testing is essential because syphilis can be asymptomatic for years. Blood tests (treponemal and non-treponemal) are the standard diagnostic method.
  • Condoms remain the foundation of prevention, but they do not eliminate risk entirely because sores can occur outside the area covered by a condom.
  • Doxy-PEP is a promising new tool — A single dose of doxycycline within 72 hours of condomless sex reduces syphilis risk by 70–80% in studied populations.
  • Regular STI screening — at intervals appropriate to your risk level — is the most reliable way to catch syphilis early, before it can progress or spread.
  • Partner communication and notification are critical for breaking transmission chains.
  • Stigma is the enemy of prevention. Syphilis is an infection, not a judgment. Seeking testing and treatment is a responsible act that protects both you and your community.

Your sexual health is part of your overall health. Track your screening appointments, stay informed about your risk, and never hesitate to get tested. Using WatchMyHealth's physician visit tracker, you can log STI screening dates, set reminders for follow-ups, and maintain a private record of your preventive care — making it easier to stay on top of one of the most important aspects of your wellbeing.