Syphilis in Women: Stages, Tests and Penicillin Cure

• Syphilis is a bacterial STI that progresses through primary, secondary, latent and (rarely) tertiary stages over months to years if untreated.
• It is curable. Early syphilis usually needs just one injection of benzathine penicillin; later stages need three weekly injections.
• The primary sore (chancre) is painless and is often hidden inside the vagina or on the cervix, so many women never notice it.
• Every pregnant woman in India is screened for syphilis through NACO's PPTCT programme, because untreated maternal syphilis can cause stillbirth or congenital syphilis.
• Testing and treatment are free at NACO ICTCs and Designated STI/RTI Clinics, and penicillin is one of the cheapest medicines in all of medicine.
• Both partners must be treated together, and you should still get tested even if neither of you has any symptoms.

Syphilis is caused by a spiral-shaped bacterium called Treponema pallidum. It enters the body through tiny breaks in the skin or the moist lining of the genitals, mouth or anus during sexual contact, multiplies at that spot, and then spreads through the bloodstream to almost every organ over time.

What makes syphilis unusual is that it moves through clearly defined stages, and between those stages it can go completely silent for months or years. During the silent (latent) phase a woman feels perfectly well, yet the infection is still present and can still be passed to a baby in pregnancy.

Before penicillin became available in the 1940s, syphilis was a feared and often fatal disease. Today it is fully treatable, and the same antibiotic that worked eight decades ago still works, because the bacterium has never developed meaningful resistance to penicillin.

In India, sustained screening has made a real difference. Syphilis prevalence in pregnant women has fallen from around three percent in the 1990s to below one percent at most NACO surveillance sites. It remains more common at STI clinics (roughly two to four percent) and in some higher-risk groups, and congenital syphilis in newborns still occurs, which is why screening and treatment continue to matter.

Syphilis spreads mainly through unprotected vaginal, anal or oral sex with a partner who has the infection. It is most contagious during the primary and secondary stages, when bacteria are present in the sores and rash. After about two years of untreated infection, sexual transmission becomes very unlikely.

The second major route is from mother to baby during pregnancy, called congenital syphilis. The bacterium crosses the placenta, and the risk of passing it on is highest (around 70 to 100 percent) when the mother has early-stage syphilis. This is the reason syphilis is part of the routine STI screening done in pregnancy in India.

Syphilis is not spread by sharing toilets, towels, utensils, food, swimming pools or by ordinary household contact. The bacterium does not survive well outside the body and needs direct contact with a sore, mucous membrane or the bloodstream.

Condoms reduce the risk of syphilis but do not remove it completely, because a sore can sit on skin that the condom does not cover, such as the base of the penis, the scrotum, the groin or the lips. Used consistently, condoms still cut the risk meaningfully and protect strongly against other infections, so they remain worth using. Internal female condoms are another option, and our guide on how effective condoms really are explains what to realistically expect.

Syphilis classically moves through four stages. Not everyone passes through all of them, and the stages can overlap, but this framework helps explain why the infection is so easy to miss.

Primary syphilis appears as a single, painless ulcer called a chancre, usually two to twelve weeks (on average about three weeks) after exposure. It is firm, round and clean-looking, which helps tell it apart from the painful sores of genital herpes. In women the chancre is often on the cervix or inside the vagina, where she cannot see or feel it, so primary syphilis frequently goes unnoticed. It heals on its own in three to six weeks, which can falsely reassure you that the problem has gone away while the infection quietly spreads.

Secondary syphilis develops a few weeks to a few months later, as the bacteria spread through the blood. The classic sign is a coppery rash that can appear on the palms and soles, one of the few rashes that does this, along with the trunk and limbs. Other features include flat moist patches in the genital area, greyish patches in the mouth, patchy hair loss, fever, tiredness and swollen glands. These symptoms are often mild and also fade on their own.

Latent syphilis is the silent phase after the rash settles. There are no symptoms at all, but the infection is still present and is picked up only on a blood test. It is split into early latent (within the first year) and late latent (beyond a year). Most women with syphilis are actually diagnosed here, usually through antenatal screening, when a routine blood test comes back positive.

Tertiary syphilis affects around a fifth to two-fifths of untreated people, years to decades later, and can damage the heart, brain, nerves, bones and skin. It is almost entirely preventable, because treatment at any earlier stage stops the disease in its tracks. Nervous-system involvement (neurosyphilis) can occur earlier too, which is why any unusual neurological or psychiatric symptoms in someone with syphilis are taken seriously.

Because Treponema pallidum cannot be grown in the lab like most bacteria, syphilis is diagnosed with blood tests that look for antibodies, and two types are used together.

Non-treponemal tests (VDRL and RPR) become positive within a few weeks of infection, rise when the disease is active and fall after successful treatment. They are excellent for screening and for tracking whether treatment is working, but they can occasionally flag a false positive in pregnancy, autoimmune conditions or some other infections.

Treponemal tests (TPHA and FTA-ABS) detect antibodies specific to the syphilis bacterium. They turn positive early and usually stay positive for life, even after a cure.

In India, labs and NACO programmes typically start with a VDRL or RPR. If that is reactive, a TPHA is done to confirm. A reactive VDRL with a positive TPHA confirms syphilis; a reactive VDRL with a negative TPHA points to a false positive that should be investigated. The VDRL "titre" (such as 1:8 or 1:32) helps gauge how active the infection is and falls after good treatment.

Syphilis is treated with benzathine penicillin G, a long-acting injection into the muscle that keeps bacteria-killing levels in the blood for over a week. It is cheap, reliable and provided free through NACO programmes. The dose depends on the stage:

• Primary, secondary or early latent syphilis (under a year): a single injection of 2.4 million units, usually split between two injection sites.
• Late latent, unknown-duration or tertiary syphilis (not neurosyphilis): the same dose once a week for three weeks.
• Neurosyphilis or eye involvement: intravenous penicillin in hospital for 10 to 14 days.

Many people develop a short flu-like reaction within a few hours of the first penicillin injection for early syphilis. This is called the Jarisch-Herxheimer reaction, and it happens because large numbers of bacteria are killed at once, releasing substances that trigger the body's immune response. It is not an allergy and is not a reason to stop treatment.

Typical features are fever, chills, headache, muscle aches and a temporary worsening of the rash or sores. It usually peaks within six to eight hours and settles within a day. Rest, fluids and paracetamol are all that is needed.

The reaction can feel alarming if no one warned you, especially because it starts just after a treatment meant to make you better. A simple heads-up from your clinician prevents most of the worry.

In pregnancy this reaction deserves extra care, because the fever can occasionally trigger contractions. Even so, treatment must never be delayed, because untreated syphilis is far more dangerous to the baby. Pregnant women are usually observed after the first injection, with attention to the baby's heartbeat and any signs of early labour.

Congenital syphilis is when the infection passes from mother to baby during pregnancy. It is one of the most preventable causes of stillbirth and newborn death worldwide, which is why both NACO and the World Health Organization run dedicated elimination programmes.

Without treatment, around 40 percent of pregnancies in women with active syphilis end in miscarriage, stillbirth, newborn death or a baby born with the infection. Early-stage maternal syphilis is the most likely to be passed on. A baby with congenital syphilis may have liver and spleen enlargement, jaundice, anaemia, a rash on the palms and soles, a blocked runny nose and bone changes, with later problems such as notched teeth, eye damage and hearing loss if not treated.

Under NACO's PPTCT programme, every pregnant woman in India is offered syphilis screening (alongside HIV) at her first antenatal visit, usually as part of her first-visit pregnancy blood tests. A reactive result is confirmed with TPHA, and treatment is started promptly, ideally completed at least 30 days before delivery to fully protect the baby. Women with ongoing risk are re-tested in the third trimester.

The good news is that when a mother is treated in time, outcomes are excellent. Babies born to mothers with syphilis are checked at birth and treated with penicillin if needed. The cases that still occur in India are mostly in women who miss antenatal care or come to it late, which is why early, regular check-ups matter so much. Untreated syphilis is also one cause among several behind stillbirth, where families have rights and aftercare support.

Late, or tertiary, complications develop in roughly 20 to 40 percent of untreated people over many years. The key point is that they are almost completely preventable by treatment at any earlier stage. Once structural damage occurs, antibiotics stop it getting worse but cannot undo what has already happened.

Cardiovascular syphilis affects the aorta, the main artery from the heart, decades after infection. It can cause a weakened, ballooning aorta or a leaky aortic valve.

Neurosyphilis can affect the brain and nerves, causing problems such as difficulty walking, stroke-like episodes, memory loss or psychiatric changes. Anyone with syphilis and new neurological symptoms needs spinal-fluid testing.

Gummas are destructive lumps that can form in the skin, bones or internal organs. They heal well with penicillin, though some scarring may remain.

The take-home message is simple. These outcomes sound frightening, but they belong to an era before routine screening. A blood test and one injection at an early stage prevent all of it.

Syphilis is easy to miss, so it is worth getting tested rather than waiting for obvious symptoms. See a doctor or visit a NACO STI clinic if any of the following apply.

Syphilis carries heavy stigma in India, often because it is wrongly imagined as a rare, shameful disease of the past. The reality is very different: it is a common, treatable bacterial infection, picked up by a routine blood test and cured with cheap antibiotics. The stigma, not the disease, is usually the harder problem, and it falls especially hard on married women diagnosed at antenatal screening, who may be blamed even when they are not the source.

Telling a partner can feel daunting. NACO clinics and gynaecology counsellors can help with neutral framing, such as "the test means we both need treatment." A written note from the clinic that a husband can read in his own time sometimes works better than a face-to-face confrontation, and a trusted family doctor can help in some households. These conversations sit within the wider, sensitive topic of consent and sex within Indian marriages.

If you fear that disclosure could lead to violence, your safety comes first. A clinician can help with neutral wording, and you can reach out to support services such as Sakhi One Stop Centres or the national women's helpline on 181 for safety planning.

For a woman dealing with an antenatal diagnosis, the medical part is reassuringly simple: complete your treatment on time, make sure your partner is tested and treated, and attend every follow-up. Done in time, the diagnosis does not change the health of your baby. The family conversation is a separate matter that you handle with whatever support you have.

Prevention rests on three things working together: barrier protection, regular screening to catch silent infections, and prompt treatment of partners.

Condoms cut the risk of syphilis and protect well against other infections, and they are widely available in India, often free at NACO clinics. Regular screening matters because so much syphilis is silent: it is recommended for women with new or multiple partners, a previous STI, a partner with an STI, or those using HIV PrEP, as well as before planning a pregnancy. Pregnant women are screened automatically under PPTCT.

If you are mapping out your sexual health more broadly, it helps to think about the other infections that travel in the same circles, including Chlamydia in Indian Women: Symptoms, Testing and Treatment, Gonorrhea in Women: Symptoms, Testing and Treatment in India, Trichomoniasis (Trich) in Indian Women: Symptoms, Tests, Cure and HIV, since testing for one is a good moment to test for all.

• WHO — Syphilis fact sheet
• WHO — Congenital syphilis and the elimination of mother-to-child transmission
• NACO — National Guidelines on Prevention, Management and Control of RTIs/STIs
• CDC — Syphilis Treatment and Care (STI Treatment Guidelines)
• NHS — Syphilis overview, symptoms and treatment