Viral hepatitis Flashcards
(57 cards)
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
