Syphilis

Causative Organism of Syphilis

Syphilis is caused by the spirochete bacterium Treponema pallidum.

Transmission of Syphilis

Primarily transmitted through direct contact with an open lesion, typically during sexual activity, and can be transmitted from mother to fetus.

Primary Stage of Syphilis

Occurs 1-3 weeks after exposure and is characterized by the development of a painless ulcer called a chancre.

Chancre

A painless ulcer that occurs at the site of entry during the primary stage of syphilis.

Secondary Stage of Syphilis

The most contagious stage presenting with sore throat, enlarged lymph nodes, fever, weight loss, and widespread rashes.

Latent Stage of Syphilis

Characterized by the absence of clinical signs and symptoms, divided into early and late phases based on duration.

Tertiary Stage of Syphilis

Occurs years after initial exposure, manifesting in forms such as gummas, cardiovascular complications, and neurosyphilis.

Congenital Syphilis

Transmission of T. pallidum from mother to fetus, often leading to severe complications in untreated infants.

Direct Fluorescent Staining

A method more sensitive and specific than darkfield microscopy for diagnosing syphilis.

Reagin

An antibody produced in response to syphilis infection that reacts with cardiolipin.

Cardiolipin

A lipid released from damaged cells during syphilis infection.

Non-Treponemal Tests

Tests that detect antibodies against cardiolipin, such as VDRL and RPR, primarily used for screening.

Treponemal Tests

Tests that detect antibodies specifically against T. pallidum antigens, used as confirmatory tests.

False-Positive Reagin Tests

Can be caused by conditions such as pregnancy, autoimmune diseases, and infections; confirmed by treponemal tests.

False-Negative Reagin Tests

Can occur due to the prozone phenomenon where high antibody levels interfere with test reactions.

Most Common Test for Neurosyphilis

The VDRL test or ELISA performed on cerebrospinal fluid is commonly used for diagnosing neurosyphilis.

RPR Result in Congenital Syphilis

A reactive RPR test in infants may indicate congenital syphilis but can result from maternal antibodies.

CDC-Recommended Protocol for Syphilis Diagnosis

Traditional Algorithm: Screen with non-treponemal test (e.g., RPR) and confirm with a treponemal test (e.g., FTA-ABS).