MLT GlobeVirology: Hepatitis viruses
42 Virology MCQs on Hepatitis viruses with answers and explanations.
A blood bank screens every donation for hepatitis B infection. Which method is routinely used to detect HBsAg?
HBsAg screening uses immunoassays (ELISA or chemiluminescence), which are cheap, automated and sensitive. PCR is used mainly for viral load and NAT, not routine first-line serology.
Laboratory staff handling blood should be offered which vaccine as a routine occupational safety measure?
HBV is highly transmissible by sharps and splashes, and an effective recombinant vaccine exists; staff should confirm anti-HBs response. No licensed vaccines exist for HCV or HIV.
Hepatitis C is often called a "silent" infection. Which feature explains why screening, not symptoms, finds most cases?
Most acute HCV infections cause no symptoms, yet many become chronic and slowly lead to cirrhosis. Cases are found by anti-HCV screening with RNA confirmation.
Which hepatitis virus is transmitted mainly by blood and body fluids rather than by the fecal-oral route?
HDV, like its helper HBV, spreads parenterally and sexually. HAV, HEV and astrovirus are shed in stool and spread fecal-orally.
Which of these viruses is primarily hepatotropic, causing acute hepatitis as its main disease?
HAV replicates mainly in hepatocytes, causing acute hepatitis. HSV and EBV only occasionally involve the liver, and HIV targets CD4 cells.
A pathology report uses the older term "hepatoma". Which tumour does it refer to?
Hepatoma is an older synonym for hepatocellular carcinoma, a malignancy strongly linked to chronic HBV and HCV infection.
In hepatitis B, liver cell damage results mainly from the immune attack on infected hepatocytes. Which cells mediate it?
HBV itself is not directly cytopathic; CD8 T cells recognising viral peptides on MHC class I kill infected hepatocytes, causing hepatitis.
After exposure to hepatitis B, which marker usually appears first in serum, even before symptoms?
HBsAg is the earliest serological marker, detectable 1-10 weeks after exposure. HBeAg follows shortly, and anti-HBc appears with the onset of symptoms.
A hepatitis B patient is positive for a marker that indicates active replication, high DNA levels and high infectivity. Which marker is it?
HBeAg correlates with active replication, high HBV DNA polymerase activity and high infectivity. Seroconversion to anti-HBe usually indicates lower replication.
Which type of vaccine is used to prevent hepatitis A?
Licensed hepatitis A vaccines (e.g. Havrix) contain whole HAV inactivated with formalin and adsorbed to alum. Recombinant HBsAg vaccines are for hepatitis B.
The current hepatitis B vaccine contains which component?
Hepatitis B vaccine is HBsAg produced by recombinant DNA technology in yeast; protection is shown by anti-HBs ≥10 mIU/mL.
Which statement about hepatitis A is INCORRECT?
HAV never causes chronic infection or a carrier state. It is milder in children than adults, confers lifelong immunity, and vaccine is recommended for risk groups.
Several people develop jaundice, diarrhoea and raised transaminases about four weeks after eating raw shellfish. Which virus is most likely?
HAV is spread fecal-orally, including via filter-feeding shellfish, and causes acute hepatitis with jaundice after a 2-6 week incubation. Norovirus from shellfish causes vomiting within 1-2 days.
Detection of which specific IgM is the standard laboratory test for acute infection with the fecal-orally spread picornavirus of the liver?
Acute hepatitis A is diagnosed by IgM anti-HAV; IgG anti-HAV indicates past infection or vaccination. IgM anti-HBc is for acute hepatitis B.
Donated blood is routinely screened for a flavivirus-family (Hepacivirus) agent that infects only humans, spreads by blood and often causes chronic hepatitis. It is:
HCV is an RNA virus of the Flaviviridae (genus Hepacivirus), transmitted parenterally and chronic in most infected people. HBV is a DNA hepadnavirus.
Which hepatitis virus is defective and can replicate only in a person also infected with HBV, because it borrows HBsAg for its envelope?
Hepatitis delta virus is a satellite RNA agent coated with HBsAg, so it needs HBV co-infection or superinfection. HBV vaccination therefore also prevents HDV.
A nurse fully immunised against hepatitis B years ago, and never infected, would be expected to have which serological profile?
The vaccine contains only HBsAg, so vaccinees develop anti-HBs alone. Anti-HBc appears only after natural infection.
A patient is positive for HBsAg and IgM anti-HBc, and negative for anti-HBs. This indicates:
HBsAg shows current infection and IgM anti-HBc shows it is recent. Vaccination produces anti-HBs only, and past infection shows anti-HBs with total anti-HBc.
In a patient with hepatitis B, a positive HBeAg indicates:
HBeAg is released during active replication and correlates with high HBV DNA and infectivity. Seroconversion to anti-HBe usually shows falling replication.
Which is usually the first serologic marker detected after hepatitis B infection?
HBsAg appears 1–10 weeks after exposure, before symptoms and before any antibodies. Anti-HBs appears last, during recovery.