Viral Hepatitis Flashcards
microbiology of Hep A
a hepatovirus; a small, unenveloped symmetrical RNA virus which shares many of the characteristics of the picornavirus family
prevalence of hep A is highest in? (3 continents, 1 country)
south america, africa, southeast asia, and greenland
how is hep A transmitted?
fecal-oral via contaminated food/water
how does hep A manifest?
acute illness with flu-like sx, maybe N/V/D, icterus/jaundice
HAV IgM indicates?
acute exposure to hep A
HAV IgG indicates?
prior exposure OR vaccination
treatment of hep A
supportive, usually mild
close contacts to a pt with acute exposure to hep A should?
receive hep A immune globulin and vaccination
microbiology of Hep B
a member of the hepadnavirus group, double-stranded DNA viruses which replicate, unusually, by reverse transcription
prevalence of hep B is highest in?
southeast asia, africa, japan, northern canada and alaska
how is hep B transmitted?
parenteral, sexual, or perinatal contact
of those exposed to hep B, what % develop chronic HBV? Fulminant?
1%, 4%
what does it mean if a pt is positive for the HB surface antigen, and what test must be done next?
they are infected with HBV; the next test is for IgM anti-HBc to determine if it is acute (IgM+) or chronic (IgM-)
a person who has received the Hep B vaccine will be negative for all tests except?
antibody to HB surface antigen (HBsAb)
positivity to HBcAb and HBsAb implies?
immunity due to natural infection that has been fought off
a patient with all negative tests except for HBcAb (anti-HBc+) has?
one of several options: 1) resolved infection, 2) false+, so needs vaccine, 3) “low-level” chronic infxn, or 4) resolving acute infxn (in the window)
what is the most common form of HBV transmission in the West? In high prevalence areas (Asia/Africa)?
sexual/parenteral in the West; vertical in Asia, Africa
HBV immune tolerance occurs in ______-acquired HBV, manifests with (high/low) viral replication, (+/-) for HBeAg, and (+/-) for liver dz sx
perinatally; high viral replication; HbeAg+; no sx of liver dz (nl ALT)
during their 20s or 30s, patient with perinatally acquired HBV progress to the _________ stage, in which they are positive on which HBV tests? What is their ALT level?
immune clearance stage; positive for HBeAg, anti-HBe and sometimes anti-HBc (IgM); ALT spikes
inactive carriers of HBV show what lab results? Biopsy results?
low levels of DNA and ALT; HBeAg NEGATIVE, but anti-HBe positive; liver biopsy may show active dz
the “pre-core mutant” is?
an HBeAg negative form of chronic hepatitis where the patient has developed an alternate form of the virus that does not produce HBeAg (the patient has anti-HBe but no HBeAg)
resolution of chronic HBV infection is (common/rare) and patients who resolve HBV still have ______ even after clearance (risk of reactivation in immunosuppressed)
rare; cccDNA
hep D is tranmitted by?
parenteral or sexual
hep D is a ____ virus that is only seen in the setting of __________
delta (defective RNA virus); chronic hep B
how is hep D dependent on hep B?
requirs HB surface antigen to replicate
where is hep D endemic?
Mediterranean area
HDV is most likely in a patient with progressive liver dz and _____ hep B DNA
inactive/suppressed
microbiology of hep C
enveloped single-stranded RNA virus with 6 major genotypes
HCV is transmitted?
parenterally (sexual transmission very rare)
HCV is of particularly high prevalence in?
the middle east, Egypt
HCV is of intermediate prevalence in?
eastern europe, mediterranean, south america, asia
HCV is (more/less) likely to result in chronic hepatitis than HBV
more
which HBC serotype is most common in the US? Which is most difficult to treat?
GT 1; GT 1
which genotype is found in Egypt and the Middle East?
GT 4
the majority of patients infected with HIV (resolve infx/get chronic HCV)
chronic HCV (85%)
the majority of patients with chronic HIV (become stable/develop cirrhosis)
become stable (80%)
the majority of patients with HCV cirrhosis (are stable/die)
stable (75%)
HCV is the leading indication for what procedure?
liver transplant
the majority of patients with chronic HCV have what symptoms?
none or fatigue, nonspecific complaints
if a screening exam shows a high ALT, what HCV test should be performed?
anti-HCV
if a patient is positive for anti-HCV, what test should be performed next?
HCV RNA to determine whether the infection is present or cleared
factors promoting progression or severity of HCV infection
alcohol intake, steatosis, age > 40, HIV or chronic HBV co-infection, male gender
common extrahepatic manifestations of HCV
arthralgia, skin manifestations, HTN, sicca syndrome (mouth, eyes)
hepatitis E is most similar to what other hepatitis?
hep A
hep E is (acute/chronic), icteric, and self-limiting
acute
how is hep E transmitted?
fecal-oral via contaminated water
is there a strong case for animal to human transmission of HEV?
NO
how long is the incubation period for HEV, and what causes damage to the liver?
2-10 weeks; immune-mediated rxn
clinical manifestations of HEV are ____
highly varied; may cause icterus
HCV illness in _____ is milder, but in _____ can be fatal
children; pregnant women
