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52 Cards in this Set
- Front
- Back
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What 4 viruses are within the Herpes virus group?
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1. EBV
2. CMV 3. Herpes Simplex 4. Varicella-Zoster |
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What is the herpes group characterized by?
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Latency
Recurrence |
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What diseases does EBV cause?
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1. Infectious mono
2. Chronic active EBV (chronic fatigue syndrome) 3. Burkitt's lymphoma 4. Nasopharyngeal carcinoma |
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How is EBV transferred?
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Orally
Blood transfusions Placenta |
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What 3 things are used to diagnose infectious mono?
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1. Clinical features
2. Relative/abs lymphocytosis with >10% reactive lymphs. 3. Demonstration of heterophile antibody |
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In what populations is the heterophile more demonstrated?
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Adults: 90-98% seropositive
Children: <50%; less spcfc. |
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What is a heterophile antibody?
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Ab stimulated by 1 Ag which reacts w/a completely unrelated antigen of different mammal.
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How does heterophile Ab relate to EBV?
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The EBV antigen cross reacts with RBCs from horse, sheep, and ox.
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What are 3 methods used to detect heterophile antibody?
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1. Paul and Bunnell
2. Davidsohn 3. Rapid slide tests |
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What is the Paul-Bunnell screening test?
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-Hemagglutination test
-Mix inactivated Pt serum + Sheep RBCs. -Look for agglutination |
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What are the drawbacks of the Paul-Bunnel test?
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Does not distinguish btwn Ab against EBV, serum sickness, or Forssman; NOT SPECIFIC.
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What is the Davidsohn differential etst?
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Modified Paul-bunnell test;
-guinea pig RBCs absorb out the Forssman antigen. -horse RBCs absorb out CMV antigen. -absorbed serum then tested. |
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What are drawbacks of the davidsohn test?
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Timeconsuming.
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What is the monoslide test?
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a faster alternative to davidsohn test.
-Reagent A has both guinea pig and horse RBCs. -Horse cells are 'suped up' so the test is more senstive. |
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Cite 4 situations when specific EBV antibody testing is done:
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1. Confirm heterophile neg adult case of infectious mono.
2. In cases of childhood mono. 3. Cases w/out classic symptoms 4. Immunocompromised patients |
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What are the 4 types of eBV antibodies?
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1. Anti-EB viral capsid Ag
(EB-VCA) 2. Anti-EBV early Ag (EBV-EA) 3. Anti-EBV nuclear Ag (anti-EBNA) 4. Anti-EBV membrane Ag |
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When do EBV antibodies appear?
-Anti-EB-VCA -Anti-EBV-EA -Anti-EBNA |
Viral capsid:
-IgG is 4-7 days; lifelong -IgM indicates acute infection. Early Ag: -Indic. acute inf, gone in 3mo Nuclear Ag: not there in acute, appears in convalescent stage. |
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What antibodies would be positive in Burkitt's lymphoma and Nasopharyngeal carcinoma?
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-IgG Anti-VCA
-Anti-EBV-EA. |
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What antibodies are present during the reactivation phase?
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Anti-VCA (IgG)
Anti-EBV-EA Anti-EBNA |
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What type of testing is used to test for specific EBV Abs?
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-ELISA
-Immunoflourescence. |
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In whom is Cytomegalovirus life-threatening?
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Immunocompromised
Immature infants |
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What can congenital CMV progress to?
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Cytomegalic inclusions disease.
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What causes congenital CMV infection in infants? (2 things)
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1. Primary infection of mom
2. Reactivation of mom |
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What 3 methods are usually used to diagnose CMV?
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1. Urine or blood culture in shell vial assay, with DFA for confirmation.
2. Serological methods - ELISA 3. PCR |
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What specimen should serology methods be done on? What spcf methods?
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Paired sera; there are no good IgM assays.
ELISA, C' fixatn, IFA, RIA, LA. |
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What is the most common test for CMV?
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elisa
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When is IgM preferred over paired sera?
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I don't know yet
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What 4 serology assays are used to detect herpes simplex virus?
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1. Elisa
2. Compl. fixation 3. Indirect IFA 4. Indirect hemagluttination |
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What antibodies are detected in HSV?
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Paired sera or IgM
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Why is serology used to test for Varicella-Zoster virus?
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To detect immune status.
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What types of tests are done for VZV?
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1. Elisa (mostly)
2. Complement fixation (insensitive) |
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What types of tests are done for Rotavirus?
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-EIA - for antigen in stool; VERY sensitive!!
-PCR in ref labs -EM in research |
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Why do the MMR, and how?
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for immune status
ELISA, HAI, Compl. fix, IFA |
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What types of tests are done for Rubella?
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-EIA
-Comp fix -HAI -IFA |
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What does a torch panel test for?
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Toxoplasma
Rubella CMV HSV |
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If the ToRCH is done on an infant, what would indicate infection?
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IgM; if IgG is found, that's impossible, must be mom's.
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What viruses are included in a normal respiratory panel?
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1. RSV (resp synct virus)
2. Parainfluenza (croup) 3. Adenoviruses 5. Coxsackie virus |
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What tests are used to detect RSV?
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-Elisa
-Comp fix |
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what tests are used to detect parainfluenza?
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-Elisa
-Comp fix -HAI |
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What test are used to detect adenoviruses?
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-Elisa
-Comp fix -HAI |
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what does a nasal wash specimen screening test for?
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-RSV
-Influenza A/B -Parainfluenza 1,2,3 -Adenovirus |
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What are 5 types of HIV screening tests?
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1. ELISA (best)
2. Rapid - OraQuick and UniGold 3. Orasure EIA on oral mucosal transudate 4. Urine tests 5. Home tests |
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what are 3 types of confirmatory tests for HIV?
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1. Western blot (gold standard)
2. Indirect Immunofluorescent Ab 3. Radioimmunoprecipitin (RIPA) |
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what type of testing for HIV is done on babies? Why?
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PCR; b/c antibody from the mother will affect ELISA/Western blots.
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What data is used to monitor HIV status?
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-CD4 lymph count
-Viral load testing |
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What testing is used to distinguish fresh vs. old infection of HIV?
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-RNA and p24 assays; detects the virus before seroconversion.
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What is the decreased sensitivity EIA used for?
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to indicate a nonreactive recent infection; would be negative in recent infection.
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How does West Nile virus normally present?
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80% Asymptomatic
20% symptoms of flu |
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Who are we really concerned about contracting WNV?
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Immunocomp, older, infants
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what is the gold standard for WNV diagnosis?
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serological testing
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what 2 serological tests are used to diagnose WNV?
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1. IgM capture ELISA (MAC)
2. Plaque reduction neutralization tests (PRNT) |
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what specimens are used for these tests?
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1. serum
2. CSF 3. maybe urine |
