Micro - Virology (Hepatitis) Flashcards
Pg. 162-163 Hepatitis viruses Hepatitis serologic markers
What are the different Hepatitis viruses? What kinds of viruses (i.e., genome & name) is each?
(1) HAV - RNA picornavirus (2) HBV - DNA hepadnavirus (3) HCV - RNA flavivirus (4) HDV - RNA delta virus (5) HEV - RNA hepevirus
What are the signs and symptoms of all hepatitis viruses?
Episodes of fever, jaundice, elevated ALT and AST
How is HAV transmitted? What other hepatitis virus is transmitted this way?
Fecal-oral; HEV (fecal-oral, especially with waterborne epidemics); Think: “the vowels hit your bowels”
How is HBV transmitted? What other hepatitis virus is transmitted this way?
Parenteral, sexual, maternal-fetal; HDV
How is HCV transmitted?
Primary blood, IVDU, post-transfusion
How is HDV transmitted? What other hepatitis virus is transmitted this way?
Parenteral, sexual, maternal-fetal; HBV
How is HEV transmitted? What other hepatitis virus is transmitted this way? In what context is HEV especially transmitted?
Fecal-oral; HAV; Especially with waterborne epidemics; Think: “the vowels hit your bowels”
Which hepatitis viruses are associated with carriers? Which are not?
CARRIERS: HBV, HCV, HDV; NON-CARRIERS: HAV, HEV
What is the incubation period of HAV? What other hepatitis virus(es) share(s) this incubation period?
Short (weeks); HEV (also HDV superinfection)
What is the incubation period of HBV? What other hepatitis virus(es) share(s) this incubation period?
Long (months); HCV (also HDV co-infection)
What are the incubation periods of HDV, and in what contexts?
Superinfection (HDV after HBV) - Short; Co-infection (HDV with HBV) - Long
What is the incubation period of HCV? What other hepatitis virus(es) share(s) this incubation period?
Long; HBV (also HDV co-infection)
What is the incubation period of HEV? What other hepatitis virus(es) share(s) this incubation period?
Short; HAV (also HDV superinfection)
What is the difference between HDV superinfection and co-infection?
Superinfection - short incubation period (Infection with HDV after developing chronic HBV); Co-infection - long incubation period (Acute infection of both HBV and HDV)
Which hepatitis viruses pose an increased risk for Hepatocellular carcinoma? Which do not?
HCC RISK - HBV, HCV, HDV; NO HCC RISK - HAV, HEV
How does HBV lead to increased HCC risk?
Integrates into host genome, acts as oncogene
How does HCV lead to increased HCC risk?
From chronic inflammation
Why are HAV and HEV able to have fecal-oral transmission?
Naked viruses do not rely on an envelope so they are not destroyed by the gut
Describe how HBV creates its viral proteins.
In HBV, the DNA polymerase has both DNA- and RNA-dependent activities. Upon entry into the nucleus, the polymerase functions to complete the partial dsDNA. The host RNA polymerase transcribes mRNA from viral DNA to make viral proteins. The DNA polymerase then reverse transcribes viral RNA to DNA, which helps form new particles.
What are 3 important characteristics to note about HAV?
(1) Asymptomatic (usually) (2) Acute (i.e., short incubation period) (3) Alone (no carriers); Think: “3 A’s for HAV”
What are 2 important characteristics to note about HDV?
(1) Defective virus (2) Dependent on HBV; “Think: 2 D’s for HDV”
What is the outcome of superinfection of HDV?
Superinfection –> decreased (i.e., worse) prognosis
What are 3 important characteristics to note about HEV?
(1) Enteric (2) Expectant mothers (3) Epidemic; Think: “3 E’s for HEV”
In what patient population does HEV have a high mortality?
High mortality in pregnant women
What serological marker is best to detect active hepatitis A?
Anti-HAV (IgM antibody to HAV)
What does Anti-HAV (IgG) indicate?
IgG antibody indicates prior HAV infection and/or prior vaccination
Which Anti-HAV (IgM or IgG) protects against reinfection?
Anti-HAV (IgG)
What is HBsAg, and what does it indicate?
Antigen found on surface of HBV; indicates hepatitis B infection
What is Anti-HBs, and what does it indicate?
Antibody to HBsAg; indicates immunity to hepatitis B
What is Anti-HBc? What do the IgM versus IgM versions of Anti-HBc indicate?
Antibody to HBcAg; IgM = acute/recent infection; IgG = prior exposure or chronic infection
What is Anti-HBc?
Antibody to HBcAg
Again, what is Anti-HBc? When is it positive?
Antibody to HBcAg; Positive during window period
What is HBeAg? What does it indicate?
A second, different antigenic determinant in the HBV core (in addition to HBcAg); HBeAg indicates active viral replication and therefore high transmissibility
What is Anti-HBe, and what does it indicate?
Antibody to e antigen; indicates low transmissibility
Draw the hepatitis virus particle, labeling the following: (1) DNA polymerase (2) DNA genome (3) Core (HBcAg) (4) Coat protein (HBsAg) (5) its approximate size.
See p. 163 in First Aid (figure on left)
Draw the hepatitis virus particle, labeling the following: (1) DNA polymerase (2) DNA genome (3) Core (HBcAg) (4) Coat protein (HBsAg) (5) its approximate size.
See p. 163 in First Aid
What is the relation between ALT and AST in viral versus alcoholic hepatitis?
In viral hepatitis, ALT > AST; In alcoholic hepatitis, AST > ALT.
What are the antigens associated with hepatitis virus? What are the associated antibodies?
SECES: SE are antigens, CES are antibodies
In acute HBV, what serological markers are used for detection?
(1) HBsAg (2) HBeAg (3) Anti-HBc IgM
Diagram the following hepatitis virus serological markers on a graph of months after exposure (x) versus titer (y): (1) HBeAg (2) HBsAg (3) Window period (4) Anti-HBe (5) Anti-HBs (6) Anti-HBc.
See p. 163 in First Aid (bottom graph)
In the window period of hepatitis infection, what serological markers are used for detection?
(1) Anti-HBe (2) Anti-HBc IgM
In chronic HBV (high infectivity), what serological markers are used for detection?
(1) HBsAg (2) HBeAg (3) Anti-HBc IgG
In recovery from hepatitis infection, what serological markers are used for detection?
(1) Anti-HBs (2) Anti-HBe (3) Anti-HBc IgG
Once a patient is immunized from hepatitis infection, what serological markers are used for detection?
Anti-HBs
In chronic HBV (low infectivity), what serological markers are used for detection?
(1) HBsAg (2) Anti-HBe (3) Anti-HBc IgG
