Immunology Unit 4: Syphilis Serology

Flashcards for Syphilis Serology, covering etiology, epidemiology, signs and symptoms, diagnostic terms, and evaluation methods.

What spirochete (bacteria) causes syphilis?

Treponema pallidum

How is Treponema pallidum typically observed due to its difficulty in laboratory cultivation?

Darkfield microscopy

How is syphilis often diagnosed in the serology laboratory?

Immunochemically

What are some other Treponema pallidum variants or species and the diseases they cause?

T. pallidum (variant): Bejel; T. pertenue: yaws; T. carateum: pinta

Is syphilis a CDC reportable STD?

Yes, along with chlamydia and gonorrhea

What percentage of sexual partners with lesions develop syphilis?

30% to 50%

What social issues can exacerbate syphilis rates?

Poverty, lack of health care, lack of education, overcrowding, poor hygiene

How does Treponema pallidum enter the human body?

Through an intact mucous membrane or defects in the epithelial barrier

What is the typical incubation period before syphilis symptoms appear?

Approximately 3 weeks

What are the four stages into which syphilis progresses?

Primary, secondary, latent (hidden), and tertiary

What is the characteristic sign of primary syphilis?

A painless chancre at the entry site

How is primary syphilis typically diagnosed?

Darkfield microscopy

When does the rash of secondary syphilis typically develop?

2 to 8 weeks after the chancre appears

How is secondary syphilis diagnosed?

Serum antibodies using RPR or VDRL; TP-PA

What is the main characteristic of latent syphilis?

It is asymptomatic, but may relapse to secondary syphilis

What is the primary route of transmission during the latent stage?

Congenital transfer

How is latent syphilis typically diagnosed?

Only with serology

What are the characteristic lesions of tertiary syphilis?

Granulomas (gummas)

What body systems are commonly affected in tertiary syphilis?

Cardiovascular, CNS, and brain

How is tertiary syphilis involving the CNS diagnosed?

CSF (VDRL)

What are antireponemal antibodies?

Antibodies specific to Treponema pallidum

What are nontreponemal antibodies?

Antilipoidal antibodies directed against self or other mammalian cells, also known as Reagin antibodies

What term describes antibodies that are almost always produced with syphilis, but can also be present in other diseases?

Reagin antibodies

List some diseases, other than syphilis, where Reagin antibodies may be present.

Measles, chickenpox, hepatitis, infectious mononucleosis

What is the most widely used nontreponemal serologic procedure?

Rapid Plasma Reagin (RPR) test

What is the VDRL test primarily used for?

A flocculation test for Reagin in Cerebrospinal Fluid (CSF)

What diagnostic method uses a fluorescent-labeled antibody conjugate directly to the T. pallidum organism?

Direct Fluorescent Antibody (DFA) test

What diagnostic method uses T. pallidum as an antigen and a second labeled anti-immunoglobulin antibody?

Indirect Fluorescent Antibody (IFA) test

What type of test is the Rapid Plasma Reagin (RPR) test?

An indirect or passive agglutination test using antigen-coated charcoal particles to screen for nonspecific reagin

What is the antigen mixture composed of in the RPR test?

Beet heart and charcoal ("cardiolipin - lecithin - cholesterol")

What conditions can lead to biological false positives in RPR tests?

Herpes simplex, HIV, IV drug use, pregnancy, rheumatoid arthritis, lupus