Immunology Exam 5 Flashcards
Treponema pallidum causes which infectious disease?
Syphilis
An ulcerative disease that facilitates the transmission of HIV
Syphilis
Why is syphilis cultivation not practical for the clinical laboratory?
The organism is very sensitive to heat, cold, drying, and soap.
What is the method of transmission for syphilis?
Usually sexually and congenital via placenta
What nickname was given to syphyilis?
“The Great Imitator”
A chancre typically appears during which type of syphilis?
Primary
TRUE or FALSE:
A patient will be serum reactive for syphilis 1-3 weeks after a chancre appears.
TRUE
Rash and fever are clinical manifestations that appear during which stage of syphilis?
Secondary
What is another name for the secondary stage syphilis?
Disseminated Stage
This stage of syphilis can last for years - typically 10-30.
Latent Stage
In this stage of syphilis, the patient will be serologically positive but not always infectious
Latent Stage
What is Hutchinson’s triad?
Notches in a child’s teeth along with eye damage (keratitis) and deafness due to congenital syphilis
What causes Hutchinson’s triad?
Congenital syphilis
Gumma lesions are seen in which stage of syphilis?
Tertiary
Which stage of syphilis is neurosyphilis most often associated with?
Tertiary
TRUE or FALSE:
Neurosyphilis can be seen in all stages of syphilis
TRUE - most often seen in tertiary
Direct examination of syphilis in the lab includes dark microscopy and _______
Fluorescent antibody testing of specimen
What is the fastest method of detecting syphilis?
Dark Microscopy
Delay in examining the slide, poor specimen collected, or antibiotic treatment would cause what type of result for dark field microscopy when looking for syphilis?
False NEGATIVES
Contamination with normal flora spirochetes from the mouth or rectal mucosa would cause what type of result when testing for syphilis using dark field microscopy?
False POSITIVES
Which type of direct examination of syphilis detects the antigen and is very sensitive and specific?
Fluorescent testing
What type of fluorescent testing is used to detect syphilis?
Direct AND Indirect fluorescent antibody
Which fluorescent antibody test for syphilis requires an extra step? What is the extra step?
Indirect Fluorescent Antibody test. FITC-labeled anti-human antibody is added after the anti-Tp antibody instead of just FITC-labeled anti-Tp antibody
DEFINITION: Indicates the frequency of positive results in patients WITH a particular disease. Detects TRUE POSITIVES.
Sensitivity
DEFINITION: Indicates the frequency of negative test results in patients WITHOUT a particular disease. Detects TRUE NEGATIVES,
Specificity
TRUE or FALSE: Non-treponemal tests are used as confirmatory test due to their specificity for syphilis.
FALSE- They are screening tests that are sensitive to syphilis but they are testing patient antibodies-reagin to cardiolipin
TRUE or FALSE: Confirmatory tests for syphilis are called Treponemal tests
TRUE
Reagent used for these tests include a mix of cardiolipin antigen, cholesterol, and lecithin
Nontreponemal Tests
What is the name for the special precipitation Nontreponemal tests known as special precipitation tests called?
Flocculation
Name of the non-specific antibody utilized in nontreponemal tests
Reagin
Nontreponemal test results are USUALLY positive within how many weeks after the appearance of a chancre?
1 to 4 weeks
Prozone will cause what type of nontreponemal test result in the secondary stage of syphilis?
False negative
What are some of the infectious diseases that may cause false positives for a patient’s nontreponemal test?
TB, HIV, Measles, EBV
What are some non-infectious reasons a nontreponemal test would be falsely positive?
Drug addiction, autoimmune diseases (SLE/Hashimotos), lymphoma
TRUE or FALSE:
Pregnancy can cause a false positive nontreponemal test result
TRUE