Clin. Micro Final Exam Flashcards
(91 cards)
How many hepatitis viruses are there?
5
What are hepatitis viruses resistant to?
low pH, organic solvents, and detergents
Describe Hep A structure.
• Picornavirus, ss (+) RNA genome, naked (un-enveloped) icosahedral capsid
How is Hep. A transmitted?
Fecal-oral
What causes Hep. A symptoms?
• Symptoms not caused by the presence of HAV in the liver but by the immunological response of the host to its presence
What are Hep A. Symptoms?
o Fever, headache, vomiting
o Jaundice
o Pain in the abdomen due to liver inflammation
Hep. A causes what kind of hepatitis?
Infectious hepatitis
Describe Hep. B structure.
Hepadnavirus- DNA virus and is enveloped
Hep. B causes what kind of hepatitis?
Serum Hepatitis
HBV virions are also known as??
Dane particles
How does HBV replicate?
- Unusual because contains partial dsDNA genome which must be replicated.
- HBV enters the body via blood
- Viral DNA forms complete ds circle
- mRNA in capsid produces DNA using reverse transcriptase
- RNA is degraded leaving partial ds DNA
What are the symptoms of HBV?
Symptoms include jaundice, fatigue, abdominal pain, loss of appetite, nausea, vomiting and joint pain
How does HBV spread.
Blood, semen, saliva, & milk.
Describe Hep. C structure
Flavivirus – Enveloped, icosahedral, + ssRNA virus
Only known reservoirs for Hep. C are?
humans and chimpanzees
Hepatitis D (Delta agent), what is unique about it?
Cannot code for its own surface protein and thus in order to produce more virus particles, it needs a helper virus; HBV
How is HDV acquired?
HDV is either acquired along with HBV (co-infection) or as a super-infection of an already HBV-infected individual
Hepatitis E, describe structure.
• HEV is a small, round, icosahedral, (+)ss RNA naked virus
How does HEV spread?
Fecal-oral route.
How long is the Incubation for HEV?
16 to 60 days
To what family of viruses does influenza belong to?
Orthomyxovirus family
Describe influenza shape.
Enveloped, ssRNA virus consisting of 8 RNA fragments
o Influenza virus A is found in???
• Found in humans and animals
o Influenza virus B is found in???
• Found in humans only, no changes in external antigens