CHAPTER 21: Spirochete Diseases Flashcards
False-positive nontreponemal tests for syphilis may occur because of which of the following?
a. Infectious mononucleosis
b. Systemic lupus
c. Pregnancy
d. All of the above
d. All of the above
In the fluorescent treponemal antibody absorption (FTA-ABS) test, what is the purpose of absorption with Reiter treponemes?
a. It removes reactivity with lupus antibody.
b. It prevents cross-reactivity with antibody to other T pallidum subspecies.
c. It prevents cross-reactivity with antibody to nonpathogenic treponemes.
d. All of the above.
c. It prevents cross-reactivity with antibody to nonpathogenic treponemes.
Which test is recommended for testing cerebrospinal fluid for detection of neurosyphilis?
a. RPR
b. VDRL
c. FTA-ABS
d. Enzyme immunoassay
b. VDRL
Advantages of direct fluorescent antibody testing to T pallidum include all of the following except
a. reading is less subjective than with dark-field testing.
b. monoclonal antibody makes the reaction very specific.
c. slides can be prepared for later reading.
d. careful specimen collection is less important than in dark-field testing.
d. careful specimen collection is less important than in dark-field testing.
Which of the following is true of nontreponemal antibodies?
a. They can be detected in all patients with primary syphilis.
b. These antibodies are directed against cardiolipin.
c. Nontreponemal tests remain positive after successful treatment.
d. The antibodies are only found in patients with syphilis.
b. These antibodies are directed against cardiolipin.
Which syphilis test detects specific treponemal antibodies?
a. RPR
b. VDRL
c. FTA-ABS
d. Agglutination
c. FTA-ABS
Which of the following is true of treponemal tests for syphilis?
a. They are usually negative in the primary stage.
b. Titers decrease with successful treatment.
c. In large-volume testing, they are often used as screening tests.
d. They are subject to a greater number of false positives than nontreponemal tests.
c. In large-volume testing, they are often used as screening tests.
An RPR test done on a 19-year-old woman as part of a prenatal workup was negative but exhibited a rough appearance. What should the technologist do next?
a. Report the result out as negative.
b. Do a VDRL test.
c. Send the sample for confirmatory testing.
d. Make serial dilutions and do a titer.
d. Make serial dilutions and do a titer.
Treponemal EIA tests for syphilis are characterized by all of the following except
a. they are adaptable to automation.
b. they are useful in monitoring antibody titers in syphilis patients undergoing therapy.
c. subjectivity in reading is eliminated.
d. they can be used to distinguish between IgG and IgM antibodies.
b. they are useful in monitoring antibody titers in syphilis patients undergoing therapy.
Which of the following tests is the most specific during the early phase of Lyme disease?
a. IFA
b. EIA
c. Immunoblotting
d. detection of B burgdorferi DNA by PCR
d. detection of B burgdorferi DNA by PCR
False-positive serological tests for Lyme disease may be caused by all of the following except
a. shared antigens between Borrelia groups.
b. cross-reactivity of antibodies.
c. resemblance of flagellar antigen to that of Treponema organisms.
d. a patient in the early stage of the disease.
d. a patient in the early stage of the disease.
A 24-year-old man who had just recovered from infectious mononucleosis had evidence of a genital lesion. His RPR test was positive. What should the technologist do next?
a. Report out as false positive.
b. Do a confirmatory treponemal test.
c. Do a VDRL.
d. Have the patient return in 2 weeks for a repeat test.
b. Do a confirmatory treponemal test.
A 15-year-old girl returned from a camping trip. Approximately a week after her return, she discovered a small red area on her leg that had a larger red ring around it. Her physician had her tested for Lyme disease, but the serological test was negative. What is the best explanation for these results?
a. She definitely does not have Lyme disease.
b. The test was not performed correctly.
c. Antibody response is often below the level of detection in early stages.
d. Too much antibody was present, causing a false negative.
c. Antibody response is often below the level of detection in early stages.
The reverse screening algorithm for syphilis testing
a. is the CDC preferred algorithm.
b. is more labor intensive than the “traditional” method.
c. has a high number of false positives that must be resolved by doing a TP-PA test.
d. is more prone to transcription errors in reporting.
c. has a high number of false positives that must be resolved by doing a TP-PA test.
Borrelia miyamotoi infection
a. may explain some cases of supposed Lyme disease where no rash was found.
b. is a new lethal tick-borne disease.
c. is carried by the common dog tick.
d. is another name for Southern Tick Associated Illness (STARI).
a. may explain some cases of supposed Lyme disease where no rash was found.
