Syphilis Is Rising in Singapore: What You Should Know and Who Should Be Tested
Last updated: 07 Sep 2026
Syphilis feels like an infection from another era. Something from a history textbook. Something that modern medicine has eliminated. This perception is wrong, and it is contributing to the infection being missed.
Globally, approximately 8 million people acquire syphilis every year, and incidence has been increasing over the past two decades. In Singapore, the picture is equally concerning. Research published in 2025 documented that syphilis incidence among men in Singapore has remained persistently high, fluctuating between 32.5 and 38.1 cases per 100,000 population from 2004 to 2018. While rates dipped briefly during the COVID-19 pandemic due to reduced sexual activity, post-pandemic recovery in transmission has been observed globally and is expected locally.
Syphilis is the third most common STD in Singapore after chlamydia and gonorrhoea. It is not rare. It is not historical. And its ability to progress silently through stages, lying dormant for years while causing increasingly serious damage, makes it one of the most consequential STDs to detect early.
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Why Syphilis Is Different From Other STDs
Most bacterial STDs either produce symptoms that prompt testing or cause localised damage that, while serious, remains confined to the reproductive tract. Syphilis does neither. It is a systemic infection that, if untreated, spreads throughout the entire body and can eventually damage the brain, heart, blood vessels, bones, and eyes.
What makes syphilis uniquely dangerous is its staged progression, with long asymptomatic periods between stages that create the illusion of resolution.
How Syphilis Progresses: The Four Stages
Primary syphilis (weeks after exposure). A single, painless sore called a chancre appears at the site of infection, typically the genitals, anus, rectum, or mouth. The chancre is firm, round, and painless, which is precisely why it is so often missed. Genital chancres may be hidden inside the vagina or rectum and never seen. Oral chancres may be mistaken for a cold sore. The sore heals on its own within three to six weeks, and the infected person assumes the issue has resolved.
It has not. The bacteria have entered the bloodstream.
Secondary syphilis (weeks to months later). A rash appears, often on the palms of the hands and soles of the feet, which is unusual for most rashes and is a classic clinical sign. Other symptoms may include fever, swollen lymph nodes, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue. These symptoms are non-specific and are frequently misdiagnosed as a viral illness, allergic reaction, or other condition. Like the primary chancre, secondary syphilis symptoms resolve on their own without treatment.
The bacteria remain in the body.
Latent syphilis (years to decades). After the secondary stage resolves, syphilis enters a latent phase during which there are no symptoms at all. The infected person feels completely well. They have no reason to suspect they carry the infection. This latent phase can last years or even decades. During early latent syphilis (the first one to two years), the infection can still be transmitted sexually. During late latent syphilis, transmission risk drops but the bacteria continue to reside in the body.
This is the stage at which the majority of undiagnosed syphilis cases sit. People who were infected years ago, whose primary chancre went unnoticed and whose secondary symptoms resolved, are living with latent syphilis without any awareness. As we discuss in our blog on STDs that can lie dormant for years, syphilis is one of the most significant examples of a dormant infection that can resurface.
Tertiary syphilis (years to decades after initial infection). In approximately 15 to 30 per cent of untreated cases, syphilis eventually progresses to the tertiary stage, which can cause cardiovascular syphilis (damage to the aorta and heart valves, potentially fatal), neurosyphilis (damage to the brain and spinal cord, causing dementia, paralysis, sensory loss, and personality changes), gummatous syphilis (destructive lesions in the skin, bones, and internal organs), and ocular syphilis (inflammation of the eye that can cause blindness).
Tertiary syphilis is devastating but entirely preventable. At every stage prior to tertiary, syphilis is curable with antibiotics. The damage from tertiary syphilis, however, is often irreversible.
Why Syphilis Is So Often Missed
The staged progression creates a pattern designed to evade detection.
The primary chancre is painless, often hidden, and self-resolving. Most people do not see a doctor for a painless sore that heals on its own. The secondary symptoms are non-specific and self-resolving. Most people, and some doctors, attribute a rash and mild flu-like symptoms to a viral illness rather than testing for syphilis. The latent phase produces no symptoms whatsoever. There is nothing to prompt testing during this phase unless the person requests screening proactively.
The result is that many syphilis cases are discovered incidentally: during routine blood donation screening, pre-employment health checks, antenatal screening during pregnancy, or when a partner is diagnosed and contacts are traced. Without these incidental detection points, latent syphilis can persist undetected for years.
How Syphilis Is Tested
A syphilis test is a simple blood draw. The standard screening approach uses a non-treponemal test (RPR or VDRL) as the initial screen, followed by a treponemal-specific test (TPHA, FTA-ABS, or similar) to confirm a positive result.
The window period for syphilis is approximately three to six weeks. Testing before this window may produce a false negative. If you have had a recent exposure, your doctor will advise on the optimal timing and whether repeat testing is needed.
At Regis Medical, syphilis testing is included in our comprehensive STD testing panel alongside chlamydia, gonorrhoea, and hepatitis B. It can also be tested individually if syphilis is the specific concern.
How Syphilis Is Treated
Syphilis is curable at every stage prior to irreversible tertiary damage. The treatment is remarkably simple: penicillin, delivered by injection. For early syphilis (primary, secondary, or early latent), a single injection of benzathine penicillin G is curative. For late latent syphilis, three weekly injections are recommended.
Treatment is highly effective, widely available, and inexpensive. The tragedy of tertiary syphilis is not that it is untreatable. It is that the person was never tested during the years or decades when a single injection would have cured them.
After treatment, follow-up blood tests (RPR titre monitoring) at 6 and 12 months confirm that the infection has been adequately treated and the titre is declining.
Syphilis and Other STDs
Syphilis frequently coexists with other STDs. The DSC (Department of Sexually Transmitted Infections) in Singapore notes that it is not uncommon for a person to be infected with more than one STD simultaneously. A syphilis diagnosis should always prompt testing for chlamydia, gonorrhoea, hepatitis B, and HIV, because the sexual exposure that transmitted syphilis may have transmitted other infections as well.
Additionally, the genital sores caused by primary syphilis increase the risk of HIV transmission, because the broken skin provides an entry point for the virus. Syphilis and HIV coinfection is a well-documented clinical pattern.
An Infection That Should Not Be Forgotten
Syphilis is curable. It is testable with a single blood draw. Treatment is a single injection for early-stage disease. And yet it remains the third most common STD in Singapore, with persistently high incidence rates that have not meaningfully declined in over a decade.
The gap is not in treatment availability. It is in testing. People who have been unknowingly carrying latent syphilis for years. People who assumed a painless sore was nothing. People who attributed a rash to an allergic reaction. People who have never been tested because they did not know they should be.
A syphilis test at Regis Medical takes a single blood draw. A comprehensive STD screening covers syphilis alongside the other infections that commonly coexist. A visit to our GP clinic starts the conversation with complete confidentiality and no judgement.
Syphilis is an infection from every era, including this one. The only thing that has changed is that we now have the tools to find it and cure it before it causes the damage it was known for centuries ago. You just have to be tested.
STD tests for peace of mind
Patient-first, Holistic, Dedicated Healthcare
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