Gastroenterology

  • Viral Hepatitis

  • What type of virus is hepatitis A?

  • RNA virus

  • Approximately what percentage of hepatitis A infection results in fulminant hepatic failure?

  • Less than 1%

  • How long does infection with hepatitis A confer immunity?

  • Lifelong – no reinfection once recovered however relapse is possible

  • Contamination of which food commonly causes transmission of hepatitis A?

  • Shellfish

  • Hepatitis A infection is endemic in which 2 regions?

  • 1) Africa

    2) South America

  • What is the approximate incubation period in hepatitis A infection?

  • 15 to 50 days, average 28 days

  • Following infection with hepatitis A, over what time period is the onset of jaundice?

  • Within 2 weeks

  • In hepatitis A infection how long are infected individuals contagious?

  • During the incubation period and approximately 1 week after the onset of jaundice

  • In pregnant women what effect can hepatitis A infection have on labour?

  • Increased risk of preterm labour

  • In hepatitis A infection approximately how long after exposure to the virus do serum aminotransferase levels peak?

  • 1 month

  • In which organ does the hepatitis A virus replicate?

  • Liver

  • What route is the hepatitis A virus shed?

  • Stool

  • In the majority of patients what is the time period for full clinical and biochemical recovery of hepatitis A infection?

  • 2 to 3 months – by 6 months in almost all patients

  • In hepatitis A infection what are the 2 commonest extrahepatic manifestations?

  • 1) Rash

    2) Arthralgia

  • Which antibodies are present in acute hepatitis A infection?

  • IgM anti-HAV antibodies

  • How long after infection with hepatitis A can IgM antibodies remain detectable?

  • 3 to 6 months

  • Which antibodies are present in the recovery period of hepatitis A infection?

  • IgG anti-HAV antibodies

  • In which 2 conditions would anti-HAV IgG be present in the absence of anti-HAV IgM?

  • 1) Previous hepatitis A infection

    2) Vaccination against hepatitis A

  • What type of virus is hepatitis B?

  • DNA virus

  • Which 2 bodily fluids are the main routes of hepatitis B virus transmission?

  • 1) Blood

    2) Semen

  • What is considered the best method of preventing hepatitis B virus transmission?

  • Pre-exposure hepatitis B vaccination

  • How soon after acute exposure to hepatitis B virus does hepatitis B surface antigen (HBsAg) appear in the serum?

  • 1 to 10 weeks after exposure

  • Following acute exposure to hepatitis B virus does hepatitis B surface antigen (HBsAg) appear before or after an increase in serum alanine aminotransferase (ALT)?

  • Before an increase in serum ALT

  • In patients who recover from hepatitis B infection, how long after exposure to the virus does hepatitis B surface antigen (HBsAg) usually become undetectable?

  • After 4 to 6 months

  • After what time period does the presence of hepatitis B surface antigen (HBsAg) indicate chronic hepatitis B infection?

  • More than 6 months

  • Approximately what percentage of immunocompetent adults with acute hepatitis B progress to chronic infection?

  • Less than 5%

  • The disappearance of hepatitis B surface antigen (HBsAg) is followed by the appearance of which serological marker?

  • Hepatitis B surface antibody (anti-HBs)

  • How long does hepatitis B surface antibody (anti-HBs) remain in the majority of patients?

  • Lifelong – may disappear in some patients

  • Which serological marker can be used to make the diagnosis of hepatitis B infection during the ‘window period’?

  • Hepatitis B core antibody - IgM antibodies against hepatitis B core antigen (IgM anti-HBc)

  • Is hepatitis B surface antigen (HBsAg) typically present in the ‘window period’?

  • No

  • Is hepatitis B surface antibody (anti-HBs) typically present in the ‘window period’?

  • No

  • Approximately how long can the ‘window period’ in hepatitis B infection last?

  • Weeks to months

  • During which stages of hepatitis B infection is hepatitis B core antibody (anti-HBc) detectable?

  • Throughout the course of infection

  • Which is the main antibody class of hepatitis B core antibody (anti-HBc) during acute infection?

  • Immunoglobulin M (IgM)

  • Which is the main antibody class of hepatitis B core antibody (anti-HBc) in patients who recover from acute infection?

  • Immunoglobulin G (IgG)

  • Which is the main antibody class of hepatitis B core antibody (anti-HBc) in chronic infection?

  • Immunoglobulin G (IgG)

  • In which 2 conditions can hepatitis B surface antibody (anti-HBs) be present?

  • 1) Immunity due to recovery from acute hepatitis B i.e. previous (inactive) infection

    2) Immunity due to hepatitis B vaccination

  • Which antigen is considered a marker of HBV replication and infectivity?

  • Hepatitis B e antigen (HBeAg)

  • How does the presence of hepatitis B e antigen (HBeAg) usually relate to HBV DNA levels?

  • Association with higher levels of HBV DNA

  • In acute hepatitis B infection what does the disappearance of HBV DNA indicate?

  • Recovery

  • Which is the only serological marker to be positive in immunity due to hepatitis B vaccination?

  • Hepatitis B surface antibody (anti-HBs)

  • What type of virus is hepatitis C?

  • RNA flavivirus

  • In acute hepatitis C infection are the majority of patients symptomatic or asymptomatic?

  • Asymptomatic – less than 25% show clinical features

  • Which malignancy is chronic hepatitis C infection associated with?

  • Hepatocellular carcinoma (HCC)

  • What are the 2 commonest methods of transmission for hepatitis C virus infection?

  • 1) Intravenous drug use

    2) Blood transfusion

  • Which serological marker confirms the diagnosis of hepatitis C virus infection?

  • HCV RNA (real-time polymerase chain reaction assay)

  • Which serological marker confirms exposure to hepatitis C virus?

  • Anti-HCV antibody

  • What does the presence of anti-HCV antibody and the absence of HCV RNA indicate?

  • Previous (inactive) infection

  • Do anti-HCV antibodies cross the placenta?

  • Yes

  • Which 2 serological markers should be tested for in suspected acute hepatitis C virus infection?

  • 1) Anti-HCV antibody

    2) HCV RNA

  • How soon after exposure to hepatitis C virus do most patients develop detectable anti-HCV antibodies?

  • 2 to 6 months after exposure

  • Following exposure to hepatitis C virus, which becomes detectable first – HCV RNA or anti-HCV antibody?

  • HCV RNA

  • What does the presence of both HCV RNA and anti-HCV antibody typically indicate?

  • Chronic hepatitis C virus infection

  • What is the approximate rate of spontaneous clearance of hepatitis C virus after infection?

  • 20-45%

  • Cryoglobulinaemia may occur as an extra-hepatic manifestation of which viral hepatitis?

  • Hepatitis C infection

  • Approximately what percentage of patients with essential mixed cryoglobulinaemia have hepatitis C infection?

  • More than 90%

  • Which thyroid disorder may be an extra-hepatic manifestation of hepatitis C infection?

  • Thyroiditis

  • Which renal condition may be an extra-hepatic manifestation of hepatitis C infection?

  • Membranoproliferative glomerulonephritis

  • How are many of the extra-hepatic manifestations of hepatitis C infection affected with resolution or treatment of hepatitis C infection?

  • Improvement or resolution

  • Which viral hepatitis infection should be tested for in patients with Sjogren’s syndrome?

  • Hepatitis C virus infection

  • What type of virus is hepatitis D (HDV), also called hepatitis delta virus?

  • RNA virus

  • The presence of which virus is necessary for hepatitis D virus infection?

  • Hepatitis B virus

  • Which serological marker is generally tested for diagnosis of hepatitis D virus infection?

  • Anti-HDV antibody

  • What is the only antigen associated with HDV?

  • Hepatitis D antigen (HDAg)

  • How is HBV replication affected in HDV-infected patients?

  • Suppression of HBV replication

  • What type of virus is hepatitis E?

  • RNA virus

  • Which animal is often implicated in zoonotic transmission of hepatitis E virus?

  • Pig

  • Which serological marker is the main test of chronic HEV infection?

  • HEV RNA

  • What are the 3 main sources of hepatitis E virus transmission?

  • 1) Contaminated food and water

    2) Blood transfusion

    3) Mother-to-child transmission

  • Are most patients with acute HEV infection asymptomatic or clinically unwell?

  • Asymptomatic or mildly symptomatic

  • How does pregnancy affect the risk of acute liver failure in acute HEV infection?

  • Increased risk

  • Which serological marker is the main test of acute HEV infection?

  • Anti-HEV IgM antibody

  • How is acute HEV infection usually managed?

  • Supportive management

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