syphilis (sĬf´əlĬs), contagious sexually transmitted disease caused by the spirochete Treponema pallidum (described by Fritz Schaudinn and Erich Hoffmann in 1905). Syphilis was not widely recognized until an epidemic in Europe at the end of the 15th cent. Some medical historians have proposed that syphilis first appeared in Spain among sailors who had returned from the New World in 1493, while others have concluded from archaeological evidence that it probably originated in the Old World but may have been confused with leprosy. A study (pub. 2008) that examined the evolutionary relationships among Treponema bacteria supported the idea that the spirochete originated in the New World, with some researchers suggesting it may have mutated into a sexually transmitted disease in Europe.
The most prevalent mode of transmission is by sexual contact; infection by other means is possible, but its occurrence depends upon an open wound or lesion to permit invasion of the organisms. A person with syphilitic sores has an increased chance of contracting AIDS from an infected partner. An infected mother can transmit the disease to her fetus; 25% of such pregnancies end in stillbirth or death of the infant, and another 40% to 70% will result in a baby with congenital syphilis, which, if untreated, can progress to late-stage syphilis and cause serious damage to the brain and other organs.
The development of syphilis occurs in four stages. The primary stage is the appearance of a painless chancre at the site of infection (often internal) about 10 days to 3 months after contact. There are no other symptoms, and the chancre disappears with or without treatment.
The secondary stage usually begins 3 to 6 weeks after the chancre with a rash over all or part of the body. Active bacteria are present in the sores of the rash. Headache, fever, fatigue, sore throat, patchy hair loss, and enlarged lymph nodes may be present. The signs of the secondary stage will disappear with or without treatment, but may reappear over the next 1 to 2 years.
Untreated syphilis then goes into a noncontagious latent period. Some people will have no more symptoms, but about one third will progress to tertiary syphilis, with widespread damage to the heart, brain, eyes, nervous system, bones, and joints. Late syphilis can result in mental illness, blindness, severe damage to the heart and aorta, and death.
Neurosyphilis, infection of the nervous system, frequently occurs in the early stages in untreated patients. There may be no symptoms, mild headache, or severe consequences such as seizures and stroke. Its treatment and course are complicated by concomitant HIV infection.
Diagnosis and Treatment
Diagnosis is made by symptoms, blood tests (required by many states before issuing marriage licenses), and microscopic identification of the bacterium. Until the advent of penicillin in the 1940s, treatment for syphilis was with mercury, arsenic, and bismuth. Penicillin is the antibiotic of choice for all stages of syphilis treatment, but penicillin-resistant organisms have complicated treatment of the disease. Even late-stage syphilis can be cured, but damage that has already occurred cannot be reversed. Despite available treatment, the incidence of syphilis in the United States was on the rise until 1990, when it began declining significantly; since 2000, it has risen again.
See also Ehrlich, Paul.