Microbiology of the Hepatitis Viruses Flashcards
What group of people living in the U.S. accounts for greater than 50% of Americans living with chronic HBV?
Asian and Pacific islanders, most likely acquired in-utero from parents that were not originally from the U.S.
- hepatocellular carcinoma is leading cause of CANCER death in this population.
What type of virus is Hepatitis A (HAV)? (SKETCHY)
Picornavirus (+ ss RNA) naked icosahedral virus.
Does infection with HAV confer lifelong immunity?
YES :)
What type of virus is Hepatitis E (HEV)?
Hepeviridae (+ ss RNA) naked icosahedral virus.
*resembles Calicivirus
What HEV genotype is common in the U.S. and the world, respectively?
U.S.= genotype 3; porcine zoonotic disease World= Asia, Middle East, Africa, and Central America.
What group of people must you be most concerned with acquiring HEV?
- pregnant women (associated with fulminant hepatitis; liver failure with massive liver necrosis).
What is the Hepatitis B surface antigen (HBsAg)?
surface glycoprotein, which has 3 initiation codons:
1. small
2. medium (Dane particle)= infectious particle
3 large
*combination of these form the HBsAg
What happens once antibody is generated against HBsAg?
you have immunity against infection/reinfection :)
*antibody will remove small, medium, and large antigens/particles
When will antibody against HBsAg (HBsAB) be detected in the blood?
Not until the HBV infection is resolved!
What are the 2 CORE antigens?
- HBcAg= core
- HBeAg= envelope (secreted form of the core protein)
* they will each induce their own antibody response
What is Hepatitis D (HDV)?
subviral particle that uses HBsAg to form an envelope and allow spread from cell to cell.
Does HDV superinfection with HBV increase the severity of HBV?
YES
What type of viruses are Hepatitis C and G?
Flaviviruses= (+ SS RNA virus) also Yellow Fever, Dengue, and West Nile (however these are transmitted by mosquito, whereas HCV and HGV are NOT).
What is HGV also called?
GBV-C
Are many people with HCV also co-infected with HIV?
YES (30-50%)
*worsens HIV infection
What does HGV infection do to HIV co-infection?
slows HIV progression
How is HGV acquired?
via blood transfusions only
What forms of hepatitis can be asymptomatic?
all except HDV
What is the incubation period for Hepatitis B,C, and D viruses?
6 weeks to 6 months.
What is the incubation period for Hepatitis A and E?
about 4 weeks.
Is jaundice occurring as a result of HBV more or less likely to occur as a patient gets older?
MORE likely
Are you more or less likely to have chronic HBV infection if you are an infant?
MORE (90%), but more likely to be asymptomatic compared to adults (6%), whom are more likely to be symptomatic. AKA inverse relationship.
*** What is CHRONIC immune TOLERANT HBV?
- persistently NORMAL hepatic aminotransferase levels - high levels of circulation HBeAg and HBV DNA.
- usually infected prenatally (NEWBORNS).
*** What is HBeAg+ immune ACTIVE CHRONIC HBV?
- HBsAg is positive longer than 6 months.
- HBeAg is positive, anti-HBe is negative.
- High levels of HBV DNA in serum (>20,000 IU/mL).
- persistent or intermittent ELEVATION in hepatic aminotransferase level.
