Hep B Flashcards
What is Hep b?
a DNA virus of the family Hepadnaviridae
Causes acute hep and becomes chronic ONLY IN 1% of healthy adults
How many people have chronic infection?
350 million
What are most problems associated with hep B?
are with regard to chronic infection
What is hep B due to?
Mainly due to the immune reaction of the host
Best case for the oncogenicity of any virus can be made for hep B
where is it most found?
its an endemic in subsaharan Africa and the Pacific rim
incubation period of hep B?
50-150 days
Acute phase?
is clinically indistinguishable from other causes of acute hep except by serological studies
whats the marker of acute infection?
is HB surface antigen, which is a marker of infectivity but not an infectious particle in itself
this will be positive before the elevation in serum transaminases
what happens within this test?
the HBSAg will normally disappear prior to the development of the HB surface antibody, which is a marker of immunity and recovery
during the short window period when both markers are absent, an etiologic diagnosis can be made by checking for HB core IgM antibody
Other tests?
HBe antigen, a marker of high infectivity, HBe antibody, a marker of recovery, and HB DNA, a marker of high infectivity which is sometimes used to monitor therapy
HB Core antigen is only found on liver biopsy and is not routinely ordered
Symptoms of chronic infection?
usually mild and nonspecific
Lack of energy, easy fatigue, and malaise are common
myalgias, arthralgias skin rash and glomerulonephritis may occur when circulating immune complexes are present
why may chronic HBV infection go unnoticed?
until cirrhosis and even endstage liver disease is present
what are patients with cirrhosis at risk for?
high risk for liver cancer!
What is Chronic hep B characterized by?
persistent HBSAg and failure to develop HBSAb for 6 months
how many carriers spontaneously become immune?
1%
