Hepatitis I & II Flashcards
Which hepatitis viruses do not have vaccines?
HCV and HEV
How many HCV infections are there in the U.S.? How many annual deaths?
- 3.2 million
- 20,000 (more yearly deaths than HIV)
Note: both incidence and mortality are on the rise for HCV.
The HAV vaccine was introduced around ____________.
2000; as such, cases of acute HAV have precipitously dropped since then
Both HBV and HCV have been declining since roughly _________.
1990, around which time blood donations started to be screened
Give Dr. Barton’s rundown on HAV.
- Picornavirus
- Positive-sense, ssRNA
- Naked
- Causes acute infections
- Most often asymptomatic infection
- Vaccine is killed
- Passive immunity can be given (IV Ig), but this is not commonly used
- Diagnosed by anti-HAV IgM (for acute… anti-HAV IgG is for past exposure/immunization)
- Can only get once due to lifelong immunity
HAV causes jaundice more commonly in ______________.
those older than 14
The incubation period for HAV is _________.
one month
Anti-HAV IgM is ____________ with illness.
concurrent, because the hepatic damage is immune-mediated
Fulminant hepatitis occurs ___________ in HAV infections.
rarely (about 0.5% of cases)
How common is HAV infection?
Extremely common
Almost all people in the U.S. will be exposed at some point in their lives.
A new strain of __________ has been recently discovered that has an envelope.
HAV
Give Dr. Barton’s rundown on HEV.
- Naked
- Icosahedral
- Positive-sense ssRNA
- Fecal-oral transmission
- Reservoir in pigs ** (Dr. Barton emphasized this) **
- Acute, self-limiting (though 10x higher mortality than HAV)
- Causes fulminant hepatitis in pregnant women
- Diagnosed by anti-HEV IgM and/or PCR
Give Dr. Barton’s rundown on HBV.
- Hepadnavirus
- DNA virus
- Circular genome
- Partially ds
- Enveloped
- Acute and chronic infections
- Vaccine is to surface antigen (like the needle on the hippie van next to the blue S)
- Diagnosed by anti-HbSAg IgM, anti-HbCAg IgM
- Transmitted by blood contact (needles, birth, sex)
HBV has _____________ in its genome.
overlapping open reading frames
What happens to the HBV genome once it’s in the cell?
The host cell machinery “fixes” the partial dsDNA by filling in the gaps.
HBV reverse transcriptase is active immediately prior to _________________.
egress of virions
What is the incubation period of HBV?
Two to six months
Acute HBV infection is more common in _____________.
people older than age 5
_____________ will be absent in those who have chronic HBV.
Anti-HBsAg antibodies
Note: anti-HBcAg can be present in someone with chronic HBV.
How is acute HBV treated?
- In an adult, no treatment is required
* In a neonate, give passive and active vaccination
Give a rundown on HDV.
- Negative-sense ssRNA
- Circular genome
- Enveloped
- Requires HBV to replicate
What is unique about HDV replication?
It uses host RNA polymerase II to synthesize more mRNA (which is unusual because RNA pol II usually requires DNA).
HDV superinfection leads to ___________.
chronic HDV infection
Give a rundown on HCV.
- Part of the Flaviviridae
- Parenteral transmission (sex, IV drug use)
- Acute infections are subclinical
- 50% – 80% of infections lead to chronic infections
- No vaccine because of antigenic variation (that is, presence of anti-HCV antibody is not protective)
- Positive-sense ssRNA
- Enveloped
- Nonsegmented
- Treated with ribavirin, interferon alpha, and sofosbuvir
Which hepatitis virus has been shown to be transmitted by casual contact (such as toothbrushes and razors)?
HCV
Sofosbuvir inhibits _______________.
RNA-dependent RNA polymerase (NS5B)
What is the incubation period of HCV?
6 –7 weeks
What percent of those with chronic hepatitis develop cirrhosis?
10%
What genotype of HCV is most common in the U.S.?
1
It’s important that patients with chronic HCV do not _______________.
drink alcohol; even a little can accelerate the disease process
_________________ are now obsolete in the treatment of HCV.
NS3/4A protease inhibitors (such as telaprevir and boceprevir)
The inactivated HAV vaccine generates _____________ in the host.
IgG
Anti-HAV IgM indicates recent infection.
Why is it more common to have jaundice in an adult with HBV as compared to a child?
The hepatocellular damage is mediated by the immune system, not the virus itself. As such, the more robust adult immune system leads to a more robust symptom profile.
What serum pattern is characteristic of chronic HBV?
Persistent (greater than six months) HBsAg without anti-HBsAg antibody; anti-HBcAg can be present
All of the -previr drugs target __________.
HCV protease
In general, the acute phase of __________ is more mild than HBV.
HCV
How long are anti-virals given to those with chronic HBV?
Up to one year
