Syphilis is a sexually transmitted ...

Syphilis is a sexually transmitted disease (STD) caused at the spirochete Treponema pallidum. Previously known as the "great imitator," this disease can have numerous and mixed manifestations. Family physicians should understand its presentations, stage-specific diagnostic testing, and appropriate antibiotic treatments, because missed or inappropriately treated syphilis can terminate in devastating cardiovascular and neurologic disease, as well as congenital syphilis.

Epidemiology

The incidence of syphilis decreased significantly with the introduction of penicillin in the 1940 further rose sharply again with the advent of human immunodeficiency virus (HIV) infection in the 1980 From 1990 between the walls of 2000, primary and secondary syphilis infection rates decreased by dint of 89.2 percent. Despite the overall decreases, outbreaks of syphilis have lately been reported in men who have sex with men In the United States, syphilis is more prevalent in the toward the south in urban areas, in men and in blacks. (1)

Stages of Syphilis

Primary syphilis most numerous often manifests as a solitary, painless chancre that lay opens at the site of infection an average of three weeks after front to T. pallidum.

Without treatment, blood-borne spread of T pallidum athwart the next several weeks to month eventuates in secondary syphilis, which has numerous clinical manifestations. The most numerous common features are fever, lymphadenopathy, diffuse rash, and genital or perineal condyloma latum.

During the latent stage of syphilis, skin lesions analyze and patients are asymptomatic. However, serologic standards are positive for T. pallidum.

Tertiary or late syphilis bring outs years after the initial infection and can involve any organ theory The most dreaded complications are neurosyphilis and involvement of the aortic valve and root

Diagnosis

DARK-FIELD MICROSCOPY

Dark-field microscopy is the chiefly specific technique for diagnosing syphilis when an active chancre or condyloma latum is quick in emergencies (2) However, its accuracy is limited on the experience of the operator performing the exhibition the number of live treponeme in the lesion, and the neighborhood of nonpathologic treponemes in oral or anal lesions. (3)

In preparation for dark-field microscopy, the lesion is cleansed and then abraded gently with a gauze pad. one time a serous exudate appears, it is gathered on a glass slide and examined subordinate to a microscope equipped with a dark-field condenser (2) T pallidum is identified on its characteristic corkscrew appearance. (4) Given the inherent difficulties of dark-field microscopy, negative examinations onward three different days are necessary before a lesion may be considered negative for T pallidum. (4)

NONTREPONEMAL TESTS

Syphilitic infection leads to the production of nonspecific antibodies that react to cardiolipin. This reaction is the basis of traditional nontreponemal examples such as the VDRL ordeal and rapid plasma reagin test

With nontreponemal experiments false-positive reactions can occur because of pregnancy, autoimmune disorders, and infections. (56) In addition, these criterions may show a "prozone" phenomenon in which large amounts of antibody block up the antibody-antigen reaction, causing a false-negative proof in the undiluted sample. (2)

Qualitative nontreponemal trials are widely used for syphilis screening. However, their usefulness is limited according to decreased sensitivity in early primary syphilis and during late syphilis, when up to individual third of untreated patients may be nonreactive. (3)

After adequate treatment of syphilis, nontreponemal trials eventually become nonreactive. However, steady with sufficient treatment, patients sometimes have a persistent low-level positive nontreponemal criterion (referred to as a serofast reaction).

Titers are not interchangeable between different proof types. Hence, the same nontreponemal standard should be used for follow-up evaluations.

TREPONEMAL-SPECIFIC TESTS

Treponemal-specific exhibitions detect antibodies to antigenic constituents of T. pallidum. These exhibitions are used primarily to confirm the diagnosis of syphilis in patients with a reactive nontreponemal exhibition However, the enzyme immunoassay (EIA) example for anti-treponemal IgG also may be used for screening. (7) Treponemal-specific touchstones include the EIA for anti-treponemal IgG, the T pallidum hemagglutination (TPHA) proof the microhemagglutination test with T pallidum antigen, the fluorescent treponemal antibody-absorption proof (FTA-abs), and the enzyme-linked immunosorbent assay.

Treponemal ordeals have sensitivities and specificities equal to or higher than those for nontreponemal exhibitions (2,5) However, treponemal-specific tests are more difficult and expensive to perform, which limits their usefulness as screening touchstones In addition, false-positive results can present itself especially when the FTA-abs proof is used in patients with systemic lupus erythematosus or Lyme disease. (28)

Unlike nontreponemal proofs which show a decline in titers or become nonreactive with effective treatment, treponemal-specific experiments usually remain reactive for life. Therefore, treponemal-specific ordeal titers are not useful for assessing treatment efficacy.