Is syphilis still common in Singapore?

Yes - and it is rising. MOH reports several thousand new cases per year, with a notable increase among MSM and in congenital syphilis. Routine screening is recommended for anyone at risk.

Can syphilis be cured?

Yes. A single in-clinic antibiotic injection cures early syphilis (less than 2 years' duration). Later-stage and neurosyphilis require longer antibiotic courses but are still curable.

What is the window period for a syphilis blood test?

Treponemal antibodies are usually detectable from 3-6 weeks after exposure. We repeat the test at 6 and 12 weeks if the first is negative and exposure was recent.

If I had syphilis years ago, will the blood test always be positive?

The treponemal-specific test (TPHA/EIA) often stays positive for life. The non-treponemal test (RPR) titre falls after successful treatment and is used to detect new infection or reinfection.

Is the primary sore painful?

Usually no - which is why it is so easy to miss. A painless ulcer on the genitals, anus or mouth that heals on its own without treatment should always prompt a syphilis test.

How is syphilis treatment handled at Hisential?

Your personal health concierge arranges confidential serology, the penicillin injection, partner notification support and the 3/6/12-month titre follow-ups in one pathway.

Syphilis in Singapore: Symptoms, Testing & Treatment

Syphilis is a bacterial STI (also called STD) caused by Treponema pallidum that progresses through four stages. The primary sore is painless and easily missed. Diagnosis is by blood serology (window 3-12 weeks). Treatment is a guideline-directed antibiotic regimen prescribed by our medical team, with the specific course chosen based on the stage of infection. Most notified cases in Singapore are in men.

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Medically reviewed by Dr. Julian Ng · MD, SMC-registered · Pathogen: Treponema pallidum · ICD-10 A50-A53

What is syphilis?

Syphilis is a systemic bacterial infection that progresses through primary, secondary, latent and tertiary stages over months to years if untreated. Early stages are highly infectious and easily cured; late stages can cause irreversible neurological, cardiovascular and skeletal damage.

Syphilis has resurged worldwide over the past two decades. In Singapore it remains one of the three legally notifiable STIs, and no congenital syphilis cases were reported in 2023 or 2024.

Pathogen: Treponema pallidum (Spirochete bacterium).

How it spreads

Direct contact with a syphilis sore (chancre) during vaginal, anal or oral sex
Mother-to-baby in utero (congenital syphilis)
Shared needles for injection drug use
Rarely, blood transfusion (now screened in Singapore)

Who is at risk? Should I get tested?

Men who have sex with men (MSM) - the highest-incidence group globally and in Singapore
People with multiple sexual partners
Sex workers and clients of sex workers
Pregnant patients without antenatal screening
People living with HIV
Partners of people recently diagnosed with syphilis

Should I get tested? Quick self-check

Answer the questions below - your concierge can advise on the next step.

Have you noticed a painless sore or ulcer on the genitals, anus or mouth in the past 3 months?
Have you had a non-itchy rash on the palms or soles?
Have you had multiple or new sexual partners in the past 12 months?
Are you a man who has sex with men?
Has a partner been diagnosed with syphilis?
Are you pregnant or planning pregnancy without a recent syphilis screen?

Symptoms

Primary: a single painless ulcer (chancre) at the site of infection - genitals, anus, mouth - lasting 3-6 weeks then healing spontaneously
Secondary (6-8 weeks later): rash, often on palms and soles, fever, swollen lymph nodes, patchy hair loss, mucous patches
Latent: no symptoms, but blood tests remain positive (years)
Tertiary (10-30 years later if untreated): cardiovascular and neurological complications including stroke, dementia, blindness, aortic aneurysm

Asymptomatic in men

Primary chancre is painless and missed in around 30% of cases; latent syphilis is by definition asymptomatic

Asymptomatic in women

Often even harder to detect because the chancre may be on the cervix or inside the vagina and never noticed

Source: see reference [1] below.

Singapore statistics

Syphilis is legally notifiable in Singapore under the Infectious Diseases Act 1976, First Schedule, item 38.	^[5]
Reported incidence in Singapore (2024)	70.0 per 100,000 population, down from 107.1 per 100,000 in 2023^[2]
Reported incidence by sex (2024)	97.0 per 100,000 men and 41.4 per 100,000 women^[2]
Infectious syphilis (2024)	3.3 per 100,000 population, down from 6.3 per 100,000 in 2023^[2]
Congenital syphilis (2023 and 2024)	No cases reported in either year^[2]

Testing & window period

Method

Two-step serology: non-treponemal (RPR or VDRL) for activity + treponemal (TPHA/EIA) for confirmation. Dark-field microscopy or PCR of ulcer fluid for primary lesions.

Specimen

Venous blood; ulcer swab if a chancre is present

Window period

Treponemal antibody test detects infection from 3-6 weeks post-exposure; repeat at 6 and 12 weeks if exposure was recent and first test negative.

Retest

RPR titres are monitored at 3, 6 and 12 months after treatment to confirm a 4-fold drop (cure marker). Annual screening for high-risk groups.

Treatment

First-line: A guideline-directed antibiotic regimen prescribed by our medical team. The choice (a single in-clinic injection for early syphilis, or a longer course for late or neurological disease) depends on the stage of infection identified at consultation.

Alternative: Alternative oral antibiotic regimens are available for patients with a penicillin allergy. Neurosyphilis requires hospital-based intravenous antibiotics and is co-managed with a specialist.

Partner management: Sexual contacts from the past 90 days (primary) or 6-24 months (later stages) should be tested and treated presumptively.

A short-lived flu-like reaction (Jarisch-Herxheimer) can occur after the first dose - usually mild and self-limiting within 24 hours.

Follow-up

RPR titres at 3, 6, 12 months - a 4-fold drop confirms cure
Annual screening for ongoing-risk patients
HIV test at diagnosis and 3 months later
Pregnancy screening at first antenatal visit and again in third trimester

Prevention

Consistent condom use - reduces but does not eliminate risk (chancres can be outside condom-covered areas)
Regular screening every 3-6 months for MSM and people with multiple partners
Syphilis screening at every antenatal visit
Partner notification and concurrent treatment
HIV PrEP users should be re-screened for syphilis every 3 months

Vaccination

There is no syphilis vaccine. Prevention relies on screening and partner treatment.

Syphilis - frequently asked questions

Clear answers, written by our clinical team. Tap any question for its direct permalink, or reach out to your Personal Concierge for anything else.

6 questions answered

Is syphilis still common in Singapore?
Yes. Syphilis is one of three legally notifiable STIs here, and the reported incidence was 70.0 per 100,000 population in 2024, down from 107.1 per 100,000 in 2023. Men accounted for most cases, at 97.0 per 100,000 against 41.4 per 100,000 in women. Routine screening is recommended for anyone at risk.
Can syphilis be cured?
Yes. A single in-clinic antibiotic injection cures early syphilis (less than 2 years' duration). Later-stage and neurosyphilis require longer antibiotic courses but are still curable.
What is the window period for a syphilis blood test?
Treponemal antibodies are usually detectable from 3-6 weeks after exposure. We repeat the test at 6 and 12 weeks if the first is negative and exposure was recent.
If I had syphilis years ago, will the blood test always be positive?
The treponemal-specific test (TPHA/EIA) often stays positive for life. The non-treponemal test (RPR) titre falls after successful treatment and is used to detect new infection or reinfection.
Is the primary sore painful?
Usually no - which is why it is so easy to miss. A painless ulcer on the genitals, anus or mouth that heals on its own without treatment should always prompt a syphilis test.
How is syphilis treatment handled at Hisential?
Your personal health concierge arranges confidential serology, the penicillin injection, partner notification support and the 3/6/12-month titre follow-ups in one pathway.

Still have a question?

Your Personal Concierge replies within one business day - confidentially.

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References

Other STI conditions

Browse our other in-depth STI guides - each covers symptoms, asymptomatic statistics by sex, Singapore data, testing windows, treatment and prevention.

See all STI conditions →

Your personal health concierge

One dedicated contact coordinates your testing, treatment, partner support and follow-up - discreetly and end-to-end. All care is delivered by our SMC-registered medical team.