Syphilis Flashcards
characterized by the appearance of a painless sore called a chancre.
Primary Syphilis
transmission of the spirochete Treponema pallidum from the mother to the fetus, resulting in premature birth.
Conginetal Syphilis
involves a rash, fever, sore throat, and other symptoms.
Secondary Syphilis
most severe stage, causing damage to organs such as the heart, brain, and nerves.
Tertiary Syphilis
divided into early (within a year of infection) and late (more than a year after infection) stages, with no symptoms present.
Latent
an infection involving the central nervous system (CNS) and, can occur at any time after infection.
Neurosyphilis
Causative agent of Syphilis
Treponema pallidum
Family of T. pallidum
Spirochaetaceae
Mode of transmission for Syphilis:
- Direct contact (sexual contact)
- Across the placenta
- Body fluids
Initial lesion is a painless, nonbleeding ulcer
Chancre
includes skin rashes, low-grade fever, malaise, weight loss, arthralgia, and lymphadenopathy.
Secondary Syphilis
formed by coalescence or large, pale, flat – topped papules. Occurs in warm, moist areas such as the perianal area and are highly infectious. Trademark of secondary syphilis.
Condyloma lata
existing but not yet developed
Latent Phase
Can cause blindness and sensitivity
Neurosyphilis
most common complication of late syphilis. May be single or multiple, They are ordinarily indolent, slowly progressive, and indurated granulomata, with central healing and atrophic scar surrounded by hyperpigmented borders.
Gummas
syphilis lesion due to hypersensitivity reaction to treponemal antigens
Gummas
presents in the neonate as diffuse maculopapular desquamatous rash (particularly around the mouth and on the palms and soles), hemolytic anemia, jaundice, hepatosplenomegaly, abnormal cartilage and bone involvement, and mental retardation.
Conginetal Syphilis
Definitive diagnosis of syphilis is made by:
Detection of T. pallidum in:
1. CSF
2. Umbilical cord
3. Skin
4. Mucous membrane lesions
A fluorescence labeled antibody is used to detect T. pallidum in lesions.
Direct fluoresent antibody-T pallidum (DFA TP)
T. Pallidum is detected using
Darkfield microscopy and silver stains
Treponema pallidum infection causes the host to produce:
Nonspecific antibody
Reagin
Specific treponemal antibodies
detect reagin and are only used for screening
Nontreponemal antigen test
Disadvantage of nontreponemal antigen test
Cause false positive because the antibody can cross react with other diseases or conditions like pregnancy
percentage of false positives in nontreponemal antigen test is
30%
Examples of nontreponemal antigen tests
- Venereal Disease Research Laboratory (VDRL),
- Unheated serum reagin (USR),
- Rapid plasma reagin (RPR) assays.
Treponemal antigen tests use
T pallidum cells as the antigen source
Highly specific
Treponemal antigen tests
Treponemal antigen tests include:
- Fluorescent treponemal antibody absorption (FTA-ABS)
- T. pallidum particulate agglutination (TP-PA)
- Microhemagglutination T. pallidum tests.
measure the antibody (reagin) a patient has formed against cardiolipin, cholesterol, and lecithin and is read microscopically for flocculation
VDRL TEST (Venereal Disease Research Laboratory Test)
The VDRL test is positive _________ after the chancre or other lesions appears.
1-3 weeks
The only serologic test approved for testing CSF
VDRL TEST
This is a modified VDRL test in which choline-chloride EDTA is added to the VDRL antigen, and the addition of this compound allows serum that has not been heat inactivated to be tested
USR TEST (Unheated Serum Reagin)
Difference between Coagulation and Flocculation
§ Coagulation – a chemical process, thus no techniques needed for mixing. Often a salt breakdown to release charges.
§ Flocculation – a physical process, thus needs a techniques for mixing. Often times a polymer induces the settling of the particles.
Macroscopic flocculation and uses VDRL antigen with charcoal particles.
RPR TEST (Rapid Plasma Reagin)
Charcoal is trapped in the folcculation reaction
RPR
Can be semi-qualitative or qualitative
RPR
Treponemal antigen is combined with liposomes.
TP-PA TEST (T. pallidum Particulate Agglutination)
If the antibodies are present, a mat of agglutination forms in wells of a microtiter plate.
TP PA
Principle of FTA-ABS
Indirect Antibody test
_______________ of T. pallidum subsp. Pallidum is affixed into wells if microscope slides.
Nichol’s stains
In FTA-ABS, patient serum is _______________
Heat inactivated
Nontreponemal antibody is absorbed from patient serum with absorbent of _____________ of nonpathogenic treponeme.
Reiter’s strain
