Viral hepatitis Flashcards
Hepatitis ____ and ____ virus are transmitted by the fecal oral route and cause acute, self limited illness but not chronic infection
HAV
HEV
In HAV infection, injury to the liver occurs mainly due to _________
host immune response to virus
CD8 T cells, NK cells, gamma interferon
Where does HAV still occur in the US?
Coastal and southern states
chronic care institutions
day care centers
How is HAV transmitted?
fecal-oral route
most cases are sporadic- person to person transmission within households, daycare centers
Describe the causes of point source outbreaks of HAV
shellfish, raw fruits and vegetables
Describe the clinical manifestations of HAV
Self limited, clinically silent in children and mild symptoms and jaundice in adults
possible dark urine, clay colored stools, ALT and AST elevation
rarely: rashes, arthritis, optic neuritis
Fecal shedding in HAV begins _______ and can last _______
begins 1-2 weeks before symptoms of jaundice
can last until 2 weeks after symptom onset
HAV can occasionally cause _________, particularly in patients with co-morbid chronic HCV infection
acute liver failure
How is HAV diagnosed?
anti-HAV IGM is detectable as soon as symptoms occur and can be detected for up to 6 months
IgG is detectable 2-8 weeks after symptom onset and remains positive for life
What is the treatment for HAV?
supportive therapy, work restrictions if food service industry
refer for liver transplant if acute liver failure
Who should be vaccinated against HAV?
All children born in US
Patients with chronic liver disease, immunocompromised, MSM, IVDU, travelers to endemic areas
In individuals who have been exposed to HAV, what is appropriate post exposure prophylaxis?
HAV vaccine, Ig available for people over 40 with chronic liver disease
What is the most common route of HEV exposure?
contaminated water and food
person to person is less common
Who is at risk of acute liver failure with HEV?
Pregnant women especially in final trimester
What form of HEV is common in the US? In the developing world?
US: endemic form, zoonotic transmission especially from pigs
Developing world: sporadic form, spread by contaminated water, fecal-oral
How is a diagnosis of HEV made?
anti-HEV antibody in serum or HEV PCR from serum or stool
________ has been reported to be effective in treating immune suppressed patients with HEV infection
Ribavirin
What is the treatment for acute infection with HEV?
supportive care
________ is useful clinically as a serum marker of viral replication. In contrast,______ accumulates in the cytoplasm of the infected hepatocyte and is utilized for
incorporation in complete virions.
HBeAg
HBcAg
What is the major mode of injury in HBV infection?
immune mediated
HLA class I restricted cytotoxic T-cell (CTL) response directed at HBcAg/HBeAg on HBV-infected hepatocytes leads to hepatic inflammation
What is the predominant method of transmission of HBV in areas where the virus is endemic?
Vertical
HBV requires ________ in the mucosal membrane in order to infect
a break in lining of mucosal membrane
Infectivity of chronically infected persons is highest amongst those who are _______+
HBeAg+
associated with higher serum HBV DNA
Chronic infection is more likely in people who are infected with HBV when they are (young/old)
young
90% of infants
25-50% of children
5% of adults
The_____ is a marker of the infectious viral material and it is the most accurate index of viral replication
HBcAg
_________ appears during weeks 3 to 6 indicates an acute active infection at its most
infectious period, and means that the patient is infectious.
Persistence of this virological marker beyond 10 weeks shows progression to chronic infection and infectiousness.
Hepatitis B e antigen HBeAg
______ antibodies do not neutralize the HBV virus
Anti-HBc
IgG and IgM types
______ antibodies do neutralize HBV and provide protection against HBV infection
Anti-HBs
Liver biopsy in HBV infection can show:
chronic hepatitis
ground glass hepatocytes
core Ag in nucleus with immunohistochemistry
_________ was the first vaccine against human cancer
HBV vaccine
How can transmission to an infant of an HBV infected mother be prevented?
Vaccine and HBIG
How is acute HBV infection treated?
Supportive
if severe, oral antivirals
What oral antiviral drugs are used in severe acute HBV infection?
entecavir, tenofovir- nucleoside analogs
lamivudine- blocks reverse transcriptase step
What treatments are used for chronic HBV infection?
antivirals
immune modulators including interferons
_________ is a defective RNA virus that is only infectious in the setting of active HBV infection
HDV
________ of HBV and HDV usually resolves. ______, however, frequently causes chronic HDV infection and chronic active hepatitis
coinfection
superinfection
How is HDV diagnosed?
measurement of anti-HDAb IgM and IgG.
How is HDV treated?
high dose interferon
Lamivudine is helpful for HBV but not beneficial for chronic HDV
How is HDV prevented?
Prevention of HBV
List factors associated with increased risk of HCC in the setting of HBV
- higher levels of HBV DNA
- HBV infection in early childhood
- male
- cirrhosis
- smokers
- aflatoxin exposure
_________ of HBV DNA can cause disruptions in the expression of tumor supressor genes and proto-oncogenes
integration into host genome
______ should be monitored regularly in HBsAg carriers to screen for early development of HCC
serum alpha fetoprotein
liver ultrasound
List sources of HCV infection
IVDU> sexual> transfusion> hemodialysis, vertical, non-sexual contact
The risk of transmitting HCV via sexual contact is ______
low
Unlike HBV, which is a DNA virus, HCV is an RNA virus and it does not _______
integrate into the human (host) genome.
HCV genotype influences:
responsiveness to interferon alpha therapy
What is responsible for the liver damage in HCV
HCV is not directly hepatotoxic
Cytotoxic T cells
______ becomes chronic in more than 70% of infected adults
HCV
What factors cause an accelerated rate of progression of cirrhosis?
heavy alcohol use
male sex
older age at infection
HIV co infection
Unlike HBV infection, the HCC risk is not increased prior to development of ________.
cirrhosis
How is diagnosis of HCV made?
ELISA confirmed with HCV RNA PCR
What does liver biopsy show in chronic HCV?
chronic interface hepatitis
lymphoid aggregates
occasionally steatosis
How is acute HCV treated?
treatment with PEGylated interferon alpha during the acute phase reduces the risk of conversion to chronicity
What therapies used to be used for chronic HCV?
interferon + ribavirin
Patients infected with genotype ____ of HCV tend to have a poor response to interferon + ribavirin
1
______ and ______ are protease inhibitors used to treat chronic HCV
telaprevir and boceprevir
What is currently considered standard of care in HCV treatment?
combination therapy with oral direct acting agents only
