Hepatitis Virus Flashcards
Describe HAV
+ strand, does not cause chronic disease and is asymptomatic in children.
HAV transmission and pathogenesis
Fecal-oral transmission.
- Enters bloodstream through oropharynx or intestine
- Virus produced in liver, released into bile and stool.
- CD8s lyse infected cells using ADCC.
How does HAV present in the lab?
Elevated AST and ALT
Describe HBV
Blood transmission. Enveloped DNA virus; Uses Reverse transcription. Surface antigen (HBsAg) are secreted into serum of infected patient; Used as a diagnostic.
Discuss HBV serology
- HBsAg indicates the patient is infectious.
- Anti-HBs indicates immunity from virus or person has been vaccinated.
- Anti-HBc indicates previous or ongoing infection.
- IgM anti-HBc indicates acute infection.
Which two viruses can cause Hepatocellular Carcinoma?
HBV and HCV
How is HBV treated?
Antiviral drugs that target the polymerase or nucleoside analogues can be used to treat chronic disease.
Discuss Lamivudine
Analog of cytidine; Inhibits HBV reverse transcriptase. Triphosphate form inhibits DNA polymerase of HBV
Discuss HDV
Circular genome is surrounded by delta antigen. Symptoms are more severe if patient is already infected with HBV.
Describe HCV
Enveloped + strand RNA virus. Can remain cell associated. Inhibits apoptosis and interferon action allowing it to establish chronic infection.
How is HCV treated?
Ribavirin; A nucleoside analogue that inhibits nucleoside biosynthesis, mRNA capping, and RNA polymerases.
Describe HEV
Enteric virus that is spread via oral-fecal route. High mortality in pregnant women
