Syphilis

Syphilis is a sexually transmitted bacterial infection caused by Treponema pallidum. It progresses through distinct stages if untreated and can also pass from mother to child during pregnancy, causing serious complications for the baby.

• Primary stage: a usually painless sore (chancre) at the site of infection, which heals on its own within a few weeks
• Secondary stage: a widespread rash, often involving the palms and soles, along with fever, swollen lymph nodes, and general malaise
• Latent stage: no symptoms, though the infection remains present and detectable on blood testing
• Late/tertiary stage (if untreated for years): can affect the heart, brain, and other organs

• Transmitted through direct contact with a syphilis sore during vaginal, anal, or oral sex.
• Can be transmitted from mother to baby during pregnancy (congenital syphilis), which can cause miscarriage, stillbirth, or serious illness in the newborn.
• Risk is increased by multiple sexual partners and inconsistent condom use.

• Diagnosed using blood tests — a non-treponemal screening test (such as RPR) followed by a confirmatory treponemal-specific test where available.
• All pregnant women are screened for syphilis at their first antenatal visit as part of routine care.
• Clinical findings, such as a genital sore or characteristic rash, support the diagnosis alongside testing.

A single intramuscular dose of benzathine penicillin is the first-line treatment for early syphilis (primary, secondary, or early latent), with additional weekly doses used for late latent or unknown-duration infection.

Sexual partners should be tested and treated at the same time to prevent reinfection.

Pregnant women diagnosed with syphilis are treated promptly with penicillin, as timely treatment during pregnancy prevents transmission to the baby and congenital syphilis.

Patients with a penicillin allergy are referred for desensitisation or an alternative regimen under specialist guidance, particularly during pregnancy, since penicillin is the only proven treatment to prevent congenital syphilis.

• Consistent and correct condom use.
• Routine syphilis screening during antenatal care for every pregnancy.
• Regular STI screening for people at higher risk.
• Ensure sexual partners of anyone diagnosed are also tested and treated.