Viral hepatitis Flashcards
What do viruses require for replication?
Host cells and their cellular biochemical machinery
Viruses cannot replicate by themselves.
What is the composition of a virus?
DNA or RNA enclosed within a virus-encoded protein coat (nucleocapsid) and sometimes an outer-most host cell membrane-derived envelope.
How do viruses attach to host cells?
Using receptor binding proteins that target host cell surface molecules serving as virus-specific receptors.
What are common clinical symptoms of hepatitis?
- Yellowing of skin and eyes (jaundice)
- Dark urine
- Clay-coloured stool
- Nausea and vomiting
- Loss of appetite
- Fever
- Abdominal pain
- Weakness
What type of virus is Hepatitis A?
Non-enveloped ss+ve RNA picornavirus.
What is the incubation time for Hepatitis A virus?
10-50 days (average 25-30 days).
What is the mode of transmission for Hepatitis A?
Faecal-oral transmission.
Does Hepatitis A have a carrier state?
No, it resolves spontaneously without chronicity.
What is the fatality rate for icteric cases of Hepatitis A?
<0.5% (age dependent).
What type of vaccine is available for Hepatitis A?
Inactivated virus vaccine.
What does the presence of anti-HAV IgM indicate?
Recent HAV infection.
What is the structure of Hepatitis B Virus (HBV)?
Enveloped partially dsDNA hepadnavirus.
What are the primary modes of transmission for Hepatitis B?
- Parenteral
- Vertical
- Sexual transmission (close contact)
What is the incubation time for Hepatitis B Virus?
40-180 days (average 60-90 days).
What percentage of adults develop chronic infection from Hepatitis B?
5-10% (but >95% of neonates).
What type of vaccine is available for Hepatitis B?
Recombinant HBV surface antigen vaccine.
What indicates active HBV infection?
Hepatitis-B Surface Antigen (HBsAg).
What does Anti-HBsAg indicate?
Past HBV infection or immune response to HBV vaccine.
What is the incubation time for Hepatitis C Virus (HCV)?
15-160 days (average 50 days).
What is the fatality rate for icteric cases of Hepatitis C?
Up to 1%.
What is the primary treatment for Hepatitis C?
Interferon alpha together with ribavirin or direct-acting antivirals (DAAs).
What indicates recent and/or past HCV infection?
Anti-HCV Antibodies.
What is the structure of Hepatitis D Virus (HDV)?
Enveloped circular ss-ve RNA.
What does HDV require for replication?
HBV (Hepatitis B Virus).
What is the primary transmission mode for Hepatitis E Virus (HEV)?
Faecal-oral transmission.
What is the incubation time for Hepatitis E Virus?
15-60 days (average 40 days).
What is the overall fatality rate for Hepatitis E Virus?
1%-3% (15%-25% in pregnant women during outbreaks).
What type of vaccine is available for Hepatitis E?
HEV genotype 1 vaccine (available in China).
