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[Syphilis, a shepherd in a Latin poem who had the disease ]
A multistage infection caused by the spirochete Treponema pallidum.
syphilitic (sif″ĭ-lit′ik)
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, adj.
SYN: SEE: lues
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In the U.S., approx. 50,000 people contract syphilis each year (the CDC counted 46,000 cases in 2011). Nearly three quarters of all new syphilis infections in the U.S. occurred in men who have sex with men.

The disease is typically transmitted sexually by direct contact with the skin or mucous membranes of a person with active infection. A small number of congenital infections occur during pregnancy.

Spirochetes readily penetrate skin and disseminate from the site of inoculation to regional lymph nodes, the bloodstream and multiple other sites, including the central nervous system (CNS). After an incubation period of 10 days to 2 months, a papule appears on the skin that develops into a painless ulcer (chancre) characteristic of the primary stage of infection. Chancres and other syphilitic lesions are highly infectious. The genital organs are the most common site of primary infection and formation of chancres, although chancres may appear on other points of contact, e.g., the lips, mouth, anus, or rectum.

Chancres usually disappear within 3 to 6 weeks even without treatment. Within a few days to several months, the secondary stage of syphilis appears: a widespread body rash, often with systemic symptoms, e.g., fever, headache, generalized lymph node swelling, nausea, vomiting, weight loss, and malaise. Highly infectious moist, broad, pink or grayish white papules may appear in the perineum (condyloma latum), along with shallow ulcers in the mouth (mucous patches). Hair loss, usually temporary, may also occur, and the nails may become brittle and pitted. If the infection is not eradicated with antibiotics, it establishes latent infection that may cause multiple destructive changes in many organ systems years later.

In the latent (tertiary) stage of syphilis, tissue destruction occurs in the aorta, the CNS, bone, and skin. The consequences may include aortic aneurysm, meningitis, sensory and gait disturbances, dementia, and optic atrophy.

The causative agent of syphilis, T. pallidum, cannot be cultured. Diagnosis therefore relies upon the detection of suggestive serological tests, but these tests are not optimally sensitive or specific. Screening usually begins with the nontreponemal rapid plasma reagin test (RPR) or the Venereal Disease Research Laboratory test (VDRL); either test may yield inaccurate results. Both tests become reactive about 1 to 2 weeks after initial infection. If either test result is positive, a confirmatory test is done: (1) by identifying the responsible bacterium, T. pallidum on dark-field examination of material from a genital lesion; (2) with the microhemagglutination assay for antibody to T. pallidum (MHA-TP); or (3) with the fluorescent treponemal antibody absorption test (FHA-ABS). Two-stage testing increases the likelihood of obtaining an accurate diagnosis.

Descriptive text is not available for this imageThose diagnosed with syphilis may have other sexually transmitted diseases (STDs), esp. HIV infection. Public health experts recommend testing everyone with either of these diseases for the other one and for other STDs (gonorrhea, chlamydia, or trichomoniasis).

Intravenous or long-acting intramuscular preparations of penicillin are typically given to patients with syphilis. The duration of treatment varies depending on the stage of the disease and on whether there are comorbid illnesses, e.g., HIV infection, or complications, e.g., evidence of neurosyphilis. Doxycycline or tetracycline may be substituted in nonpregnant patients who are allergic to penicillin although, because of potential bacterial resistance, patients allergic to penicillin should be considered candidates for desensitization. Pregnant patients are not given tetracycline or doxycycline because they discolor primary teeth in the infant.

The patient is taught about the illness and the importance of locating all sexual contacts, treatment, and the need for follow-up care. The patient should avoid sexual contact with anyone until the full course of therapy has been completed, including previous partners who have not received adequate evaluation and treatment, if indicated, for syphilis. Contact precautions are instituted from the time the disease is suspected until 24 hr after initiation of proper antibiotic therapy and whenever draining lesions are present. Standard precautions apply. The patient is informed about safe sex practices and consistent condom use to prevent infection with syphilis and other STDs. Pregnant patients are screened for syphilis to prevent prenatal transmission. Rape victims are tested at the time of the attack and again 1 to 2 weeks later. All cases of syphilis must be reported to local public health authorities by both health care providers and laboratories.

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SYPHILIS Secondary syphilitic rash on chest and palm

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