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74 Cards in this Set
- Front
- Back
What is viral hepatitis?
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Inflammation/infectionof liver hepatocytes by one or more of many possible viruses, resulting in hepatocyte destruction and subsequent regeneration
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What are the symptoms of viral hepatitis?
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Constititional symptoms, such as fever, malaise, myalgias, nausea, and vomiting, in addition to flank pain and jaundice.
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What can be detected on physical exam in viral hepatitis?
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Tender and enlarged liver.
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What are the five major viruses that cause hepatitis?
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HAV
ABV HCV HDV HEV |
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What other viruses may cause hepatitis?
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CMV
EBV HSV Yellow fever virus |
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What is the definition of chronic hepatitis?
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Presence of the hepatitis antigen for more than 6 months.
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What viruses cause chronic hepatitis?
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HBV
HBV HDV |
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What is the most common cause of chronic hepatitis?
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HBV infection: only 10% of HBV infections are chronic versus 75% of HCV infections; however, the total number of HBV infections is much greater than HCV
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Which hepatitis virus is compromised of DNA?
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HBV
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Which hepatitis virus is unable to replicate without the help of HBV?
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HDV
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What is the mode of transmission for hepatitis viruses?
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Hepatitis A and E are both transmitted via the fecal-oral route
Hepatitis B, C, and D are transmitted parenterally (blood, semen). |
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How is hepatitis A virus transmitted?
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Fecal-oral route
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What is teh nucleic acid in HAV?
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Linear (+) ssRNA with a nonenveloped icosahedral capsid
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What viral family does HAV belong to?
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Approximately 150,000 new cases are reported in the US each year; approximately 50-75% of US adults have been infected at some point in their lives
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What is the incubation period for HAV?
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25-40 days
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How is HAV infection diagnosed?
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Serologic tests: anti-HAV IgM indicates active infection and anti-HAV IgG indicates prior infection that has since resolved
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is immunity possible for HAV?
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YES
Anti-HAV IgG lasts indefinitely and will protect against future HAV infections. |
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Is a vaccine available for HAV?
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YES
Formaldehyde-inactivated whole-virus vaccine is recommended for travelers to developing countries |
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Does HAV cause chronic hepatitis?
What is the treatment? |
NO
If given early during incubation, serum immune globulin is effective Once infection is established, treatment isonly supportive. |
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How is hepatitis B virus transmitted?
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Body fluids: blood, semen, saliva, milk
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What is the nucleic acid in HBV?
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Circular dsDNA with an enveloped icosahedral capsid.
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What is the viral family for HBV?
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Hepadnaviridae
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What is the incidence of HBV invection?
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Approximatey 300,000 new cases are reported in the US each year.
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What is the incubation period of HBV?
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60-90 days
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What is a Dane particle?
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Another name for the infectious HBV virion
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What is the pathogenesis of HBV?
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Most damage results from the cell-mediated immune response to the virus, not from the virus itself.
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What are three important antigens encoded by HBV?
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HBsAg
HBcAg HBeAg |
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What is unique about replication of HBV virus?
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Its the ony DNA virus that produces DNA by reverse transcriptase form RNA template.
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What is the prognosis for a patient with acute Hepatitis B?
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90% Effective immune response clears infection
9% Ineffective immune response results in chronic disease/carrier state <1% Fulminant hepatitis resultin gin death. |
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What are three complications of chronic HBV infection?
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1) Chronic hepatitis
2) Cirrhosis 3) Hepatocellular carcinoma |
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Why is hepatocellular carcinoma common in chronic carriers of HBV?
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Chronic hepatocyte damage secondary to the immune response to teh virus causes chronic cellular regeneration and an increased opportunity for mutagenesis
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What age group is most susceptible to chronic infection with HBV?
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Neonates, because of an immature immune system
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What percentage of neonates develops chronic infection with HBV?
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90% of HBV-infected neonates develop chronic infection as compared to 25% of infected children who develop chronic infection
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How is HBV infection diagnosed?
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Serologically
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What are the first markers of HBV?
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HBsAg
HBeAg |
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What is the window period?
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The time period following infection when HBsAg levels re undetectable, but prior to the rise in concentration and detectoin of antibodies to HBsAg (anti-HBs)
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What marker is still detectable during the window period?
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Anti-HBc
The anti-HBc must always be checked to rule out HBV infection in the window period because HBsAg and anti-HBs will be negative. |
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What is found in the blood of a patient who has cleared HBV infection?
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Anti-HBs, anti-HBc
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What is found in teh blood of a patient who has received a HBV vaccination?
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Anti-HBs only
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What is found in the blood of a patient to inindicate chronic infection with HBV?
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HBsAg present for greater than 6 months and the absence of antiHBs
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What do the serologic markers indicate during acute HBV disease?
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HBsAg
Anti-HBc (IgM) |
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What do the serologic markers indicate during the window phase of HBV infection?
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Anti-HBc (IgG)
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What do the serologic markers indicate during complete recovery from HBV?
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Anti-HBs
Anti-HBc (IgG) |
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What do the serologic markers indicate during post vaccination?
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Anti-HBs
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What do the serologic markers indicate during chronic HBV infection?
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HBsAg
Anti-HBc (IgG) |
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What is a good indicator of high transmissibility of HBV?
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HBeAg
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Is a vaccine available?
What is it? |
YES
Recombivax, a recombinant subunit vaccine derived from HBsAg is given as a 3-dose regimen to all infants and to those at high risk. Only vaccines for HBV and rabies are effective if given after exposure to the virus |
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What is the treatment for acute HBV infection?
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Supportive therapy and passive-active immunization with both hepatitis B immunoglobulin and vaccine
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What is the treatment for chronic HBV infection?
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Lamivudine and interferon are moderately effective
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How is HCV transmitted?
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Via blood; sexual transmission can occur but uncommon
HCV is the most prevalent blood-borne pathogen in the US |
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What is the nucleic acid in HCV?
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Linear, +ssRNA wit an enveloped icosahedral capsid
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What is the viral family of HCV?
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Flaviviridae
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What is the incidence of HCV infection?
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Approximately 50,000 new cases are reported in the US each year
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What is teh incubation period of HCV?
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40-120 days
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What are long term sequelae of HCV infection?
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75% of patients develop chronic hepatitis and a large percentage of these will progress to cirrhosis and hepatocellular carcinoma.
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Do HBV and HCV contain oncogenes in their genomes?
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NO
The mechanism of how HBV and HCV cause hepatocellular carcinoma is uncertain, but it is believed that fibrosis and necrosis accompanied by containing regeneratoin of hepatocytes increases the risk of genetic mutation or rearrangement that leads to hepatocellular carcinoma |
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Who is at high risk for HCV?
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IV drug users and patients on hemodialysis
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How is HCV infection diagnosed?
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ELISA detection of antibodies to HBcAg
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What is the treatment for HCV infection?
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Combination treatment with ribavirin and interferon may be effective for some patients.
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How is HDV transmitted?
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Body fluids: blood, semen, saliva, breast milk.
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What is thenucleic acid in HDV?
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Circular, enveloped -ssRNA
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What is unique about HDV replication?
Why |
HDV is a defective virus and cannot replicate on its own.
It lacks the genes for envelope protein and can only replicate when cells are coinfected with HBV. |
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What is the one protein encoded by HDV?
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Delta antigen
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How is HDV infection diagnosed?
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Detecting delta antigen or IgM antibody to delta antigen
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What is the significance of HDV infection?
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More severe acute disease and greater risk of fulminant hepatitis, cirrhosis, and hepatocellular carcinoma when coinfected with HBV.
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What is the treatment for HDV infection?
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No specific therapy, although interferon-alpha can mitigate some of the effects of the virus and HBV immunization can prevent HDV infection
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How is HEV transmitted?
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Fecal-oral transmission
HEV is a major cause of water-borne epidemics of hepatitis outside of the US |
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What is the nucleic acid in HEV?
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Linear, +ssRNA with a nonenveloped icosahedral capsid
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What is the viral family for HEV?
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Caliciviridae
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What are long-term sequelae of HEV infection?
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None because there is no chronic infection
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How is HEV infection diagnosed?
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It is a diagnosis of exclusion because no test for HEV antibody exists.
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What is the treatment for HEv infection?
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Supportive therapy because there is no antiviral therapy
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Is there a vaccine for HEV?
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NO
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What group of patients shows increased mortality with HEV infection?
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Pregnant women
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