Hep D class
Satellite, coinfect with B
Hep F class
Hep G class
HAV genome and structure
Icosahedral capsid of 4 polypeptides (VP1-4)
HAV genome distinguishing feature:
VPg (protein) on 5' end
HAV inactivated by (5 things)
Replication of HAV (6 steps)
Maturation and release
HAV produces _____ infection
HAV incubation period length
2 phases of HAV infection
1. Prodrome (flu-like, immune mediated hepatic damage)
2. Icteric (billirubinemia, jaundice, abdominal pain)
- symptoms wax/wane
- complete recovery in 99% cases
Immunogically, acute HAV infection results in
icterus is an increase in
What happens to conjugated bilirubin?
Water soluble, renal excretion
HAV replication occurs in __________ (in body)
Oropharynx or GI tract
HAV is shed in the _______
bile and feces
Does HAV cause viremia?
HAV can be detected...
in the stool before symptoms occur
Three serological peaks during HAV infection
ALT at 2 months
IgM anti-HAV at 3 months (recent infection)
Total anti-HAV (immunity
HAV transmission routes (3 categories)
Close personal contact
Blood exposure (rare)
Seroprevalence of HAV antibodies
40-70% of adults
Serological distinction between acute and past HAV infection
IgM = Acute
IgG = Past
IgM and IgG are detected by
Is RT PCR useful in detection of HAV?
It may detect earlier than serology, but it is rarely performed
Who is TwinRx not recommended for? What's the dosing schedule?
All patients under 18 years of age.
3 doses @ 0, 1, 6 months
HBV genome and structure
Genome: Circular dsDNA
HBV capsid proteins
1. Core Protein
2. Soluble core protein
What is HBeAG?
Indicator of active HBV replication phase
(it is a variant of the core protein that was modified within the cell)
HBV envelope proteins
Surface antige (HBsAG)
- S = large
- S2 = medium
- S1 - small
Unique feature of the DNA virus HBV
Encodes a RT enzyme
replicates through RNA intermediate
The first weird step of HBV replication cycle
Second and third steps?
1. After uncoating, partially double stranded DNA genome is completed by host enzymes -- becomes CCCDNA (Covalently Closed Circular DNA)
2. Four mRNAs are made (one giant one)
3. Goes to cytoplasm where the mRNAs assemble around the big one, and NEGATIVE DNA is made by Reverse Transcriptase
What happens after DNA is synthesized in HBV replication?
RNA Degrades, and the POSITIVE counterpart to the negative DNA is synthesized.
The envelope forms before this completes
HBV released from cell via ______ after assembly
HBV causes what kinds of infections?
Acute or chronic
Acute HBV incubation time
Most HBV acute patients are ________
Some Acute HBV patients progress to
Few patients progress to _________ during acute HBV infection
risks = GI bleed, coma, encephalopathy, ascites, coagulopathy)
Survival from acute HBV results in _____________
(patients will never develop chronic infection)
Fulminant Hepatitis requires...
Chronic HBV patients may...
transmit infection throughout life
Chronic HBV is definied as
longer than 6 months
Infants with perinatal HBV infection will...
almost always develop CHRONIC hep B infection
Chronic HBV = increased risk of
cirrhosis, liver cancer, liver failure
HBV infects the liver but does not...
cause direct cytopathology
_____ is the leading cause of liver transplantation in the US
Titer cuves for acute HBV
1st peak = HBsAG
2nd peak = IgM ant-iHBc (Also TOTAL anti-HBc increases here)
Last = anti-HBs
Chronic HBV, _____ and ______last much longer in serum titer
______ doesn't have a titer peak in chronic HBV
Blood, sex, contact
Transplacental (or perinatal)
Areas of highest HBV incidence
Subsaharan Afriaca, SE Asia
Acute HBV = (None)
Chronic HBV = Reverse Transcriptase Inhibitors
- Adefovir + alpha-Interferon
HBV control (3)
- Blood donation screening
- Universal precautions
- Passive or Active Vax
HBV vaccine based on ____. This is recommended for whom? Dosing Schedule?
recommended for young and high risk
3 injections (TwinRX = HAV + HBV together)
HCV genus, genome, and structure
ss+RNA (looks like Flavivirus)
HVC is classified into _______ genotypes. Which are the most common?
Types 1-3 are most common
HVC Clades nucleotides differ by 25%, but difference is not correlated to...
differences in clinical disease
HCV displays classic _____ replication
(everything happens in the cytoplasm)
Acute HCV is _______ in most patients
"Persistent HCV" definition
detectable HCV RNA for more than 6 months from the time of presumed infection
Jaundice rate in HCV patients
__________ is responsible for HCV hepatic damage
CMI leading to inflammation of the liver
Hepatocellular pathogenesis of HCV (three things)
- Miscroscopically spotted parenchymal cell degeneration
- Necrosis of hepatocytes
- MQ accumulate near the degenerating hepatocytes
Acute HCV infection shows __________multiplication
Sx of acute HCV coincide with increase in
_______ appears in serum after about 8 weeks post-HCV exposure
Highest source for HCV infection
IV drug use
Sources (3) with least prevalence for HCV infection
Vertical transmission to fetus occurs in __ % of HCV cases
% risk for HCV transmission from breastfeeding
Sexual transmission of HCV is _____ than HIV and HBV
HCV transmission between partners may be associated with ....
shared use of Razors and toothbrushes
Needlestick transmission rate for HCV is _____ than HIV
1.8% versus 0.35%
HCV treatments (3)
1. Interferon + Ribavirin
2. Pegylated Interferon alpha + Ribavirin
(3. Bocepravir + Telaprivir (protease inhibitors))
HDV needs _____ for infection
envelope protein from other virus
HDV genus, genome and structure
- ss (-) RNA, Circular
HDV RNA encodes _________ that complexes with _______
complexes with RNA
Chronic infection with HDV occurs in ___% of cases
Two types of HDV infections:
1. Co-infection (fulminant in 1%)
2. Super-infection (fulminant in 5%)
________ HDV infection is far more likely to develop into a chronic infection
Superinfection - 80-90% of patients
What is a HDV superinfection?
Infection with HDV in a patient that is already positive for HBsAG
Superinfection HDV causes rapid...
cirrhosis and hepatocellular carcinoma
alpha interferon + lamivudine
HEV genome and structure
Number of HEV genotypes? Which cause human diseases?
Only #1 causes human disease
Phases of HEV infection
Prodromal and icteric
HEV infection is _________
HEV...E stands for
Enteric + Epidemic
HEV spread via...
fecal oral route
Epidemics of HEV reporded where...
fecal contamination of drinking water is common
Most important prevention measure for HEV is
HEV chronic infection length
HEV doesn't cause chronic infection