Infectious Liver Disease Flashcards
What are the clinical presentations of viral hepatitis?
What viruses can present as each?
Acue asymptomatic w/ recovery:
- only detected through serology
- typically in children
- HAV and HBV
Acute symptomatic w/ recovery:
- non-specific prodromal phase -> icteric phase w/ tender hepatomegaly -> resolution
- common to all viral hepatitis
Actue liver failure:
- actue infection with massive hepatic necrosis
- most common w/ HAV and HEV
- can occur in HBV
Chronic hepatitis (w/ or w/o progression to cirrhosis):
- continuous or relapsing evidence of viral hepatitis for more than 6 months
- variable presentation from isolated serology/lab findings -> acute symptoms -> cirrhosis
- possible development of immune complex disease
- most HCV cases
- HBV
-HDV (superinfection > co-infection)
-HEV in immunecompromised pts (HIV)
Carrier state:
- asymptomatic, chronically infected individuals
- HBV only
What is HAV?
(transmission, risk factors, presentation)
ssRNA virus
- fecal-oral transmission, common in international travel
- acute, self-limited infection only, no chronic infection
Presentation:
- acute asymptomatic (children)
- acute symptomatic (rare; adults)
- acute liver failure
What labs are useful in identifying HAV?
How do they help to identify state of infection?
-IgM anti-HAV
-significantly elevated AST/ALT
- elevated bilirubin and alkaline phosphatase
- IgG anti-HAV not detected in acute infections and indicates immunity
Can can immunity be developed to HAV?
Is their a vaccine?
Yes, IgG anti-HAV is developed after all infections (there are no chronic HAV infections) and is protective
Vaccines exist for HAV
What is HBV?
(transmission, risk factors, presentation)
partially dsRNA virus
- parenteral, sexual, and perinatal transmission
- risk factors: IVDU, multiple sex partners, healthcare workers, HBV-positive mother
Presentation:
- acute, asymptomatic (most cases)
- acute symptomatic
- acute liver failure (rare)
- chronic hepatitis (5-10%)
- chronic carrier state
What factor is associated with progression to chronic HBV infection?
younger age of infection -> increased risk of chronic infection
How does the epidemiology and etiology of HBV infection vary globally?
Chronic infection is most common in Asia and Africa (high prevalence + vertical transmission + increased risk of chronicity with younger age)
Southern/eastern Europe have intermediate rate of chronic infection (mostly horizontal transmission through contact during childhood)
Western Europe and North America lower rate of chronic infection (transmission mostly through unprotected sex and sharing needles)
What labs are useful in identifying HBV?
How do they help to identify state of infection?
- markedly elevated AST/ALT during acute infection
- fluctuating and elevated AST/ALT during chronic infection, but less elevated than actue infeciton
- HBsAg**: indicates person is currently infected (acute or active/inactive chronic)
- HBeAg or HBV DNA: indicates currently infected AND infectious (acute or active chronic)
- IgM anti-HBc: during acute disease, eventaly disappears
- IgG anti-HBc: after acute disease/with disappearance of IgM (in both chronic and cleared)
- Anti-HBs: previously had and cleared or has been immunized, never present in chronic infection; protective
What is the window period of HBV infection?
When does it occur?
occurs following acute HBV infections
- HBsAg is undetectable and anti-HBs has not become detectable
- neither can be used to diagnose during window period
- IgM/IgG anti-HBc must be used during this period in order to diagnose
What are complications with HBV?
- polyarteritis nodosa
- liver failure
- cirrhosis (worse with HDV superinfection)
- HCC
Can can immunity be developed to HBV?
Is their a vaccine?
Yes, IgG anti-HBs is developed if infection resolves and is protective
Vaccines exist for HBV
What is HCV?
(transmission, risk factors, presentation)
ssRNA virus
- parenteral (minimal sexual or perinatal)
- risk factors: IVDU, intranasal cocaine use, HIV, prison, multiple sex partners, unsafe medical practices, healthcare workers
Presentation:
- chronic hepatitis (most cases; >80%)
- acute infection is typically asymptomatic
What labs are useful in identifying HCV?
How do they help to identify state of infection?
- marked elevation of AST/ALT (fluctuates in chronic state)
- HCV RNA
- HCV Ag
HCV Ag w/o HCV RNA inidicates previous infection
What complications occur with HCV?
- cirrhosis
- HCC
- HIV co-infection
- mixed cryoglubulinemia
What is HDV?
(transmission, risk factors, presentation)
circular defective ssRNA
- lacks cabability to self-replicate and requires HBV infection to replicate
- parenteral transmission
-IV drug users
Presentation:
- superinfection of chronic HBV -> chronic HDV infection
- co-infection with HBV -> acute HDV infection (10% still progress to chronic
- acute liver failure
