Hepatitis B Flashcards
Why is HBcAg not routinely detected?
Because HBcAg is sequestered within an HBsAg coat.
Currently available lab test for Hep B?
HBsAg Anti-HBs IgM anti-HBc IgG anti-HBc HBeAg Anti-HBe
Which Hep B lab test is most helpful in determining whether the pt is in the acute phase of viral hepatitis?
IgM anti-HBc is a marker for acute (less than 6 months ) hepatitis
- It appears soon after the onset of infection and the detection of HBsAg.
- It precedes by many weeks detectable levels of anti-HBsAg.
- It generally disappears after 6-8 months.
Which lab market indicate infectivity for Hep B?
HBeAg
It may persist for years in pt with chronic disease and is associated with high infectivity.
Which marker indicates chronicity of Hep B?
- HBsAg remains detectable beyond 6 months in chronic hepatitis.
- HBeAg may persist for years in pt with chronic disease.
- Persistent elevated ALT.
The relationship of Age of infection of Hep B and the risk of become chronically infected?
The likelihood of becoming chronically infected with hepatitis B is inversely related to the age at which the infection occurs.
What percent of Infants born to HBsAg-positive mothers will become Hep B carrier?
Up to 90%
What percent of children infected Hep B before the age of 5 will become Hep B carrier?
Between 25-50%
What percent of acutely Hep B Infected adults will become chronically infected?
6-10%
Transmission of HBV in the US?
- most HBV in fiction in the US with known routes of transmission result from sexual contact.
Hepatitis D virus
- A defective virus
- Co-infection with HBV is necessary for the replication and clinical expression of HDV
- Preventing hepatitis B through vaccination with HBV vaccine will protect against hepatitis D
Risk of seroconversion due to sharps injury from a known positive source?
HBV—-6-30% if not vaccinated
HCV—-~2%
HIV—-0.3%