Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
65 Cards in this Set
- Front
- Back
--What two stages of syphilis are most infectious? |
--Primary and secondary: stages with moist lesions |
|
--What disease states other than syphilis can cause a true positive RPR and FTA-ABS? |
--Yaws, Pinta, and Bejel --Caused by organisms morphologically and serologically indistinguishable from T pallidum |
|
--RPR |
--Non-treponemal --Serum --Flocculation --Reagin detected --Antigen used is cardiolipin --Screening --Specificity: not specific; very specific when used with EIA |
|
--VDRL |
--Non-treponemal --Specimens: heat inactivated serum/CSF --Flocculation --Reagin detected --Antigen used is Cardiolipin --Screening test --Confirmatory for Neurosyphilis --Not specific --Highly specific for neurosyphilis |
|
--EIA or Immunochemoluminescence |
--Treponemal --Serum --Specific antibody to T pallidum --Antigen used is T pallidum ssp pallidum --Screening --Specific --Confirm with RPR |
|
--FTA-ABS |
--Treponemal --Heat inactivated serum --Test principle is Indirect fluorescent antibody technique --Detects specific antibody to T pallidum --Antigen used in test is Nichols strain of T pallidum ssp pallidum --Confirmatory --Specific |
|
--What is the sensitivity of RPR for the stages of syphilis? |
--Primary: Low --Secondary: High --Latent and Tertiary: Low |
|
--What is the sensitivity of VDRL for the stages of syphilis? |
--Primary: Low --Secondary: High --Latent and Tertiary: Low |
|
--What is the sensitivity of FTA-ABS for the stages of syphilis? |
--Primary: Low --Secondary: High --Latent and Tertiary: High |
|
--What is the sensitivity of EIA or Immunochemoluminescence for the stages of syphilis? |
--Primary: Low --Secondary: High --Latent and Tertiary: High |
|
--What specific problems are encountered when performing testing to diagnose congenital syphilis? |
--Must detect baby's antibody, not the mother's --IgG will cross the placenta --Serological detection of congenital syphilis has low sensitivies and specificities |
|
--What test is used to diagnose neurosyphilis? |
--The non-treponemal VDRL test is highly specific but can have low sensitivities |
|
--What step in FTA-ABS removes non-specific treponemal antibodies from the test serum? |
--Dilution of the patient's serum with sorbent |
|
--Why should a serum reported as reactive for the RPR test be confirmed by a treponemal serologic test? |
--Subject to false positives --Due to mono, hepatitis, varicella, herpes, measles, malaria, TB, SLE, IV drug use, autoimmune, advanced age and malignancy, pregnancy |
|
--How is laboratory diagnosis of Lyme disease most often done? |
--Serology: detection of antibodies in serum |
|
--What is useful in diagnosis of early stage Lyme disease? |
--Clinical symptoms --Bulls eye rash --IgM antibody can take 3 to 6 weeks to form --Serological detection is useful in late stage disease |
|
--Why do serologic tests for Lyme disease lack specificity? |
--IFA and ELISA --Cross reactivity with other treponemal diseases (syphilis, yaws, relapsing fever, leptospirosis) --Screening test must be confirmed |
|
--How is laboratory diagnosis of Relapsing fever made? |
--Direct detection of spirochetes in body fluids by hematological stain |
|
--How is laboratory diagnosis of Leptospirosis made? |
--Serologic detection of antibodies in the serum --Serologic microagglutination test |
|
--The streptozyme test screens for which antibodies? |
--Anti-streptolysin --Anti-DNase --Anti-NADase --Anti-hyaluronidase |
|
--What does a positive Streptozyme test show? |
--Agglutination |
|
--How might a positive Streptozyme and a negative ASO latex test be explained? |
--The presence of antibodies to DNase B, streptokinase and hyaluronidase only |
|
--What are the long-term complications of Streptococcus pyogenes infection? |
--Acute rheumatic fever --Post-streptococcal glomerulonephritis |
|
--Which single test/antibody detections is the most sensitive and specific in detecting a recent Group A Streptococcus infection? |
--Anti-DNase B |
|
--In a woman of childbearing years, what confers valid evidence of rubella immunity? |
--Serologic confirmation of past rubella infection |
|
--What clinical symptoms are associated with CMV? |
--Cytomegalovirus --Congenital infection in infants whose mothers experienced primary CMV infections during pregnancy --An infectious mononucleosis-like syndrome in adolescents and young adults --Serious, often fatal, pneumonia in immunocompromised individuals, especially bone marrow transplant recipients |
|
--How is HSV tested? |
--Lesion sample can be tested for HSV antigen and inoculated into cell cultures --Antigen tests are widely available and HSV grows quickly in culture |
|
--What diseases can TORCH screen help to diagnose? |
--Toxoplasmosis --Rubella --CMV --Herpes |
|
--What groups should be tested for rubella? |
--Children --Premarital exam --Prenatal women --All women of childbearing age --Healthcare personnel |
|
--What does rubella cause in the fetus? |
--Deafness --Cataracts --Mental retardation --Stillbirth |
|
--How is CMV transmitted? |
--Cytomegalovirus --Adults: Venereal and blood products --Children: Usually from mother: Cervical secretions, breast milk, saliva, urine --Congenital: transplacental |
|
--What tests can detect WNV? |
--West Nile Virus --Antibody capture ELISA (IgM and IgG) --RT-PCR --IFA |
|
--What specimens are used for WNV testing? |
--CSF: test for WNV specific IgM Ab by ELISA --Serum: test both acute and convalescent specimens by ELISA --Tissue: brain tissue |
|
--Toxoplasma gondii |
--Can cause ocular lesions --Felines are frequent host --Can cause severe CNS abnormalities in newborns --Can be acquired in utero |
|
--What does the presence of IgM to T gondii in adults indicate? |
--Active infection |
|
--When does Congenital toxoplasmosis exhibit the most serious effects? |
--If disease is acquired during the first trimester |
|
--How is toxoplasmosis transmitted? |
--Cats are definitive hosts: Pass oocysts in feces --Eating undercooked meat --Transplacental transfer |
|
--Why might antibody testing for Rocky Mountain Spotted fever not be helpful? |
--Antibody production takes at least a week before detection |
|
--According to the CDC, which bands need to be present for the Western Blot to be positive for HIV infection? |
--Any two of the following groups: p24, gp41, gp120/160 |
|
--Human immunodeficiency virus is: |
--Retrovirus |
|
--The mode of transmission for HIV is: |
--Blood products --Congenital --Venereal --Intravenous drug abuse |
|
--What diminishes as AIDS progresses? |
--CD4 and T lymphocytes --Risk of opportunistic infection increases |
|
--HIV can affect what cells? |
--Helper-inducer subset of T lymphocytes --Macrophages --Monocytes |
|
--Which patient populations should be screened for HIV? |
--13-64 years of age --Pregnant --TB positive --Screened for STDs |
|
--What does the HIV Western Blot analysis detect? |
--Antibody to HIV in the patient's serum |
|
--How is the new CDC/APHL testing algorithm for HIV advantageous over the traditional algorithm? |
--4th generation enzyme immunoassay test detects both HIV antigen and antibody to HIV |
|
--HIV EIA |
--A screening test that detects patient antibodies directed against the HIV particle |
|
--HIV PCR |
--Used to detect viral load, or quantitate the HIV particles per unit |
|
--HIV Western Blot |
--A confirmatory test that detects and separates patient antibodies directed against specific parts of the HIV particle |
|
--Complement fixation |
--Antigen-antibody complexes fix one of the test components |
|
--Precipitation |
--Soluble antigen plus specific antibody --Immunodiffusion |
|
--Microparticle capture |
--Competitive assay using microbeads as the solid phase |
|
--Direct hemagglutination |
--Antigen is natural part of particulate or cellular antigen --Bacterial cells clumped by antibody |
|
--Passive hemagglutination |
--Antigen coated particulate carrier |
|
----Direct immunofluorescence |
--Virus specific antibody labeled with fluorescein |
|
--Enzyme immunoassay |
--Enzyme labeled anti-species globulin |
|
--Neutralization |
--Antigen is inactivated when antibody binds to it |
|
--Mycoplasma pneumoniae can cause which infection? |
--Historically diagnosed with cold agglutinins --Causes Primary atypical pneumonia --Detected through antibody production |
|
--Mycoplasma pneumoniae infections cannot be treated with beta lactam antibiotic because: |
--Lack cell wall |
|
--Borrelia burgdorferi |
--Lyme disease --Erythema chronicum migrams: skin lesion found at site of tick bite |
|
--Borrelia species |
--Relapsing fever |
|
--Leptospira interrogans |
--Leptospirosis --Weil's disease: Fatal icterohemorrhagic fever |
|
--Streptozyme Test |
--Passive hemagglutination test --Screening test: sensitive in 95% of patients with Group A Strep |
|
--Anti-streptolysin O (ASO) Test |
--Detects antibodies to Streptolysin O --Neutralization Test: titer = highest dilution that neutralizes the streptolysin O antigen which lyses RBCs |
|
--Anti-DNase B titer |
--Neutralization procedure --Blue indicator: Positive --Pink indicator: Negative --More frequently positive with acute glmoerulonephritis due to skin infections --Considered to be the single best test for the serologic detection of Group A Non-suppurative Streptococcal infections |