Syphilis Transmission: Routes, Risks, and Prevention

Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subsp. pallidum. Transmission requires direct contact with infectious lesions (chancres, mucous patches, condylomata lata) or infected body fluids.

Primary Transmission Routes

1. Sexual Contact: Vaginal, anal, or oral sex with an infected partner. Highest risk during primary (chancre) and secondary (rash, mucous patches) stages when lesions are highly infectious. Condoms reduce but do not eliminate risk if lesions are outside covered areas.
2. Vertical (Mother-to-Child): Transplacental transmission can occur at any gestational age; risk is highest in early maternal infection. Causes congenital syphilis (stillbirth, preterm birth, neonatal death, multisystem disease). Universal prenatal screening is standard.
3. Blood Exposure: Rare today due to screening. Possible via transfusion (extremely rare in screened supplies), needle-sharing, or occupational needlestick.

NOT Transmitted By

• Casual contact (hugging, kissing, sharing utensils, towels, toilet seats).
• Airborne or droplet spread.
• Swimming pools, hot tubs.

Prevention

• Consistent, correct condom use.
• Regular STI screening for sexually active individuals.
• Partner notification and treatment (expedited partner therapy where available).
• Prenatal screening at first visit, 28 weeks, and delivery in high-risk populations.

Syphilis is curable with penicillin (single dose for early stages; multiple doses for late/latent). Early detection prevents complications and onward transmission.