Syphilis

Syphilis is a bacterial sexually transmitted infection caused by the spirochaete Treponema pallidum subspecies pallidum, which affects at least 11 million people worldwide every year. Case numbers in the UK now match those seen in the 1950s. Syphilis can be transmitted by oral, anal and genital sexual contact, vertically during pregnancy, and by blood transfusion. It can present with a wide range of medical symptoms and signs, and devastating sequelae can develop decades after untreated infection. Interpretation of serological tests for syphilis requires expertise to distinguish true infection from false-reactive tests. Once confirmed, treatment usually requires long-acting parenteral preparations of penicillin, followed by prolonged follow-up. For this reason, patients found to have positive syphilis serological tests should be managed by those with relevant experience.