VIRAL SEROLOGICAL TESTS Flashcards
The only DNA hepatitis virus ; 1st discovered by Dr. Blumberg
HBV
Hepatitis virus:
Fecal-oral
Blood transmission
HAV & HEV
Hepatitis virus:
Parenteral
Sexual
Perinatal
HBV, HCV, HVD
Picornaviridae
HAV
Hepadnaviridae
HBV
Flaviviridae
HCV
Delta virus
HDV
Hepeviridae
HEV
Hepatitis with high mortality among pregnant women
HEV
Water-borne HEV Genotype
HEV 1 & 2
Zoonotic HEV Genotype
HEV 3 & 4
HBV : best indicator of early acute infection ; indicates acute of chronic HBV infection
HBsAg
Infectious form of hepatitis B virus
Dane particle
Not detected in serum because it is found only in hepatocytes
HBcAg
High levels of virus and high degree of of infectivity
HBeAg
Useful in detecting infection during the window period, indicator of current infection
Anti-HBc IgM
Life long marker of hepatitis
Anti-HBc IgG
First serologic evidence of convalescent phase
Anti-HBe
Bestows immunity to further HBV infection ; viral clearance of HBV
Anti-HBs
STATUS:
HBsAg : +
Anti-HBs : -
Anti-HBc : -
Early infection
STAUTUS:
HBsAg : +
Anti-HBs : -
Anti-HBc : +
Chronic infection
STAUTUS:
HBsAg : -
Anti-HBs : -
Anti-HBc : +
Window period
STATUS:
HBsAg : -
Anti-HBs : +
Anti-HBc : +
Recovery
STAUTUS:
HBsAg : -
Anti-HBs : +
Anti-HBc : -
Vaccination
First generation HBV test
Ouchterlony
Generation test:
Counter electrophoresis
Rheophoresis
Complement fixation
Secondary generation test
Generation test:
Reversed passive latex agglutination
ELISA
Reversed passive hemagglutination
Radioimmunoassay
Third generation tests
Aka post transfusion hepatitis
Hepatitis C
Co-infection and super infection with HBV
HDV
Clinical variant of HDV
Anti-HBc IgM: +
Co-infection
Clinical variant of HDV
Anti-HBc IgM : -
Superinfection
Differentiates co-infection from superinfection
Anti-HBc IgM
Large, complex DNA, enveloped ; latent infection with lifelong persistence in the host
Herpes infection
HSV 1 & 2, VZV, EBV, CMV, Human herpes virus (HHV-6, -7, -8)
These belong to what family
Herpesviridae
Result form intimate contact with salivary secretions from an infected individual
Epstein-Barr virus
Initial infection of EBV
OROPHARYNX
Virus infected B cells
EBV-specific antibodies
Heterophile antibodies
Autoantibodies
Aka kissing disease or glandular fever
Infectious mononucleosis
Characterized by lymphocytosis ; atypical lymphocytes (Downey cells) are observed
Infectious mononucleosis
Reacts with SHEEP cells, OX cells, and Horse cells but not with GUINEA PIG cells
Heterophile Antibodies in IM
Reacts with SHEEP cells, Horse cells, guinea pig cells, but not with BEEF CELLS (OX)
Heterophil antibodies of Forssman
Reacts with sheep, ox, horse and guinea pig cells
Heterophil antibodies in serum sickness
Screening/general test for Heterophil antibodies ; hemagglutination
Paul Bunnel test
Paul bunnel test reagent : 2% suspension of _______
Sheep RBCs
Davidson Differential test principle
Absorption-hemagglutination
Davidson differential test antigen sources
Guinea pig cells and Beef cells
Davidson differential test indicator cells
Sheep RBCs
Agglutination pattern after absorption with beef cells : WITH HIGH TITER
FORSMANN
Agglutination pattern after absorption with Guinea pig kidney cells: WITH HIGH TITER
IM
more sensitive indicator of antibodies found on im
Horse RBC
Interpretation
Peripheral blood : +
Anti-VCA IgM : +
Anti-VCA IgG : +
Anti-EBNA : -
Acute infection
Interpretation
Peripheral blood : +/-
Anti-VCA IgM : +/-
Anti-VCA IgG : +
Anti-EBNA : +
Recent infection
Interpretation
Peripheral blood : -
Anti-VCA IgM :-
Anti-VCA IgG : +
Anti-EBNA : +
Past infection
Confirmatory test for EBV infection
Immunofluorescent assays (IFA)
Blood component for cytomegalovirus
Leuko-reduced
Causative agent of chicken pox
Varicella-Zoster virus
RNA virus ; Genus Rubivirus ; family Togaviridae ; Causative agent of German measles or third disease
Rubella
Genus Morbilivirus ; family Paramyxoviridae ; highly contagious and spreads by aerosol ; pathognomonic structure: “KOPLIK SPOT” ; agent of measles
Rubeola
Requires an RNA-dependent polymerase to synthesize DNA from the RNA genome ; family Retroviridae sub family Lentiviridae ; has marked preference for T-helper cells (CD4(+))
HIV
Serves as a receptor site for HIV
T-helper cells (CD4 +)
HTLV-III (Human Lymphocytic Virus III)
LAV (Lymphadenopathy Associated Virus)
ARV (AIDS-associated Retrovirus)
These are other names of?
HIV
Pandemic HIV type
HIV-1
Less pathogenic HIV type ; has a lower rate of transmission ; discovered in 1986 in West Africa
HIV-2
Gag gene codes for
p55
Env gene codes for
gp160, go120, gp41
Glycoprotein that binds to CD4 on T cells
Gp120
Transmembrane glycoprotein
Gp41
Codes for enzymes necessary for HIV replication
Pol
p51
Reverse transcriptase
P66
RNAse
P31
Integrase
P10
Protease
Regulatory gene ; transactivator
Tat
Regulatory gene ; regulator of expression of vision proteins
Rev
Regulator gene ; negative effector
Nef
Virus (____) attaches to susceptible host cell (___)
Gp120 ; CD4
HIV replication co-receptor
CXCR4 , CCR5
Initial viral replication can be detected in the presence of increased levels of ____ antigen
p24 antigen
First antibodies to be detected are directed against the gp___ transmembrane glycoprotein, followed by the production of antibodies to the gag proteins such as p__
Gp41 ; p24
The hallmark feature of HIV infection
Decreased CD4 cell population
HIV stage: 2-4 weeks of infection ; body’s natural response to infection ; large amount of virus in the blood are very contagious
Stage 1: Acute HIV infection
HIV stage: period can last a decade of longer ; people can still transmit HIV to others ; end of this phase, a person’s viral load starts to up and the CD4 cell count begins to go down
Stage 2: clinical latency
HIV stage: most severe phase of HIV infection ; badly damaged immune system opportunistic illnesses ; end stage
Stage 3 : AIDS
CD4 count of patient with HIV
<200/mm^3
Normal CD4 count
> 1000 / mm^3
For HIV initial screening test, it detects antibodies to ____________(combination)
HIV-1, HIV-2, and HIV-1 p24 antigen
Samples that are reactive in the n initial test and nonreactive in the second test should then undergo _______ testing
Nucleic acid testing
Screening tests: ELISA
Used purified viral lysate as antigen
First-generation
Screening tests: ELISA
Used recombinant viral proteins
Second generation
Screening tests: ELISA
Relied on the double antigen sandwich assay
Third generation
Screening tests: ELISA
Detected antibody and p24 antigen
Fourth generation
Screening tests: ELISA
Multiplexed screening test that detects and differentiates all tree HIIV analyte markers: HIV-1 antibodies, HIV-2 antibodies,, and the HIV-1 p24 antigen
Fifth generation assay
Recommended by the CDC as confirmatory tests ; detect antibodies to HIV-1 and alone or to both HIV-1 and HIV-2 ; followed by the current recommended testing algorithm
Rapid tests for HIV antibodies
Nitrocellullose or nylon strips containing individual HIV proteins
Western blot
Position of low molecular weight antigen in western blot test strip
Bottom
Position of high molecular weight antigen on western blot test strip
Top
Western blot : several bonds (2/3) - indicative of??
Positive result
Western blot : no band (0) - indicative of??
Negative result
Western blot : intermediate (1/3) - indicative of??
Repeat test after 6 months
CDC recommends routine HIV testing for all persons_______ years old and annual test for high risk individuals
13-64 years old
According to criteria, a result should be reported as positive if at least two of the following bands are present: ____ ____ ____ ____
P24, gp41, and gp120/160
5Cs principle recommended by WHO
Informed CONSENT
CONFIDENTIALITY
COUNSELING
CORRECT TEST RESULT
CONNECTION (linkage to care and treatment)
Rapid diagnostic test principle
Immunochromatographic methods
Antigens detected in the presence of Plasmodium falciparum (malaria)
Histidine Rich Protein 2 (PfHRP-2)
Plasmodium Lactate Dehydrogenase (pLDH)
Plasmodium Aldolase
Polysaccharide capsule of C. neoformans becomes dissolved in the serum and CSF and can be detected by the _______ agglutination test or the ____ immunoasssay
Latex-based agglutination ; enzyme immunoassay
Aspergillosis infection involves the detection of __________ and ______ in serum
Galactomannan and B-D-Lucan (BDG)