Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum.
Once considered a declining infection, syphilis has re-emerged worldwide in recent years, with rising cases across many countries, including Australia, the United States, Europe, and Asia. This global resurgence has become a major public health challenge.

• In Australia, case numbers have increased sharply over the past decade. The Federal Government has classified syphilis as a “nationally significant communicable disease event.” In Queensland alone, more than 1,000 cases are reported annually, and sadly, congenital syphilis cases and infant deaths have also been recorded. Infection rates are especially high in some Indigenous communities, where they occur at several times the national average.
• Globally, the World Health Organization (WHO) has reported a concerning rise in syphilis across many regions. In high-income countries, the increase is particularly marked among young adults and certain high-risk groups, but developing nations are also facing growing burdens, including mother-to-child transmission.

This shows that syphilis is not just a problem in one region but a worldwide issue. Because the disease can be silent and easily missed, it is important to consider STI risks in everyday life and undergo regular testing, even if no symptoms are present.

Most infections occur through unprotected sexual contact (oral, vaginal, or anal), but syphilis can also be passed from a pregnant woman to her baby, causing congenital syphilis.
One of the challenges of syphilis is that its symptoms can disappear on their own, leading people to falsely believe they are cured. In reality, the bacteria remain in the body and can cause severe, long-term complications involving the heart, brain, nerves, and other organs.

Fortunately, syphilis can be easily detected with a blood test and cured with antibiotics (penicillin) if treated early.
If you have any concerns about infection, unexplained rashes, bleeding, pain, or if you are pregnant, please arrange for testing promptly.

Stages and Symptoms of Syphilis

Syphilis progresses through several stages. Symptoms may fade, but the infection remains active and can silently advance.

• Primary syphilis (2–12 weeks after infection): a painless sore (chancre) appears on the genitals, mouth, or anus. It may heal naturally, but the infection continues.
• Secondary syphilis (weeks to months): rash on the palms or soles, fever, swollen lymph nodes, sore throat, hair loss, and mouth ulcers.
• Latent syphilis (months to years): no outward symptoms, but the bacteria persist in the body. Many people are unaware they are infected.
• Tertiary syphilis (years later, untreated): serious damage to the heart, brain, blood vessels, eyes, and bones, potentially leading to heart failure, paralysis, blindness, dementia-like symptoms, and destructive ulcers.

Complications

Without treatment, syphilis can cause devastating effects throughout the body.

• During pregnancy: congenital syphilis may cause miscarriage, stillbirth, premature birth, or long-term disabilities such as blindness, hearing loss, bone deformities, and developmental delay.
• Nervous system (neurosyphilis): headaches, memory loss, dementia-like symptoms, paralysis, vision and hearing loss, or stroke.
• Heart and blood vessels (cardiovascular syphilis): aortic aneurysm (dangerous swelling that may rupture) or valve damage leading to heart failure.
• Skin and bones: destructive ulcers (“gummas”) that cause permanent damage.
• Increased HIV risk: syphilis sores make it easier for HIV infection to occur.

Even if syphilis appears to “go away,” it often continues silently inside the body, progressing to life-threatening disease years later. This is why early testing and treatment are essential.

Testing and Treatment

Syphilis can be diagnosed with a simple blood test.

The most reliable treatment is penicillin injection therapy. In most cases, this leads to complete cure.
Follow-up testing is necessary to confirm the infection has cleared, and partners must also be tested and treated to prevent reinfection.

References

1. CSIRO Publishing – National response to syphilis in Australia
2. Herald Sun – Deadly STI outbreak, concerning new syphilis numbers exposed
3. WHO – Global syphilis trends and congenital syphilis elimination strategy