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Syphilis is a sexually transmitted disease caused by Treponema pallidum. The organism is a thin, delicate spirochete 6 to 20 μm long that has the appearance of a helical coil on dark-field microscopy or immunofluorescence.


Human beings are the only host. Nearly all transmission is through sexual contact, although very close physical contact between mucous membranes might also permit transmission.1 Transmission by transfusion has been documented. Congenital syphilis may occur transplacentally or by passage through an infected birth canal. Long, clinically latent periods are common; the infection may persist through the patient’s lifetime with a variety of clinical manifestations. Syphilis causes significant complications if untreated and facilitates the transmission of HIV. Pediatricians may have to treat children or adolescents with acquired syphilis or infants with congenital syphilis, but the most common presenting problem is the management of a well-appearing infant born to a serologically positive mother.

Whereas syphilis rates in the United States declined between 1990 and 2000, the rates in all categories, primary and secondary, early-latent, late-latent, and congenital syphilis and all age, sex, racial, and ethnic groups increased between 2005 and 2006.2 Primary and secondary syphilis rates increased primarily in men to 5.7 cases per 100,000; however, rates increased in women as well to 1.0 case per 100,000. Rates were highest in the South and specific urban areas in other regions. The increase in rates was largely attributed to increased rates in men having sex with men, HIV coinfection and high-risk sexual behavior. In 2006, the highest rates were seen in persons ages 25 to 29 years. Reported primary and secondary syphilis cases increased to 9,756 in 2006 from 8,724 in 2005, an increase of 11.8%. The overall 2006 rate of 3.3 cases/100,000 was greater than the Healthy People 2010 target of 0.2 cases per 100,000 population.3

Congenital syphilis rates in the United States declined from 1996 to 2005 with a 14% average yearly decrease and an overall 74% decrease.2 However, the rate of congenital syphilis increased 4% between 2005 and 2006 (from 8.2 to 8.5 cases per 100,000 live births) with 349 reported cases. In 2006, 26 states, the District of Columbia, and one outlying area had rates of congenital syphilis that exceeded the Healthy People target of one case per 100,000 live births (eFigs. 288.1 and 288.2).3

eFigure 288.1.

Syphilis—reported cases by stage of infection: United States, 1941–2006.

eFigure 288.2.

Congenital syphilis—rates for infants less than 1 year of age: United States, 1997–2006 and the healthy people 2010 target.

Clinical Features

Children and adolescents who acquire syphilis follow a clinical course similar to adults. In infected children, sexual abuse must be presumed and laws require that ...

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