Hepatitis A + B Flashcards
What are the five main hepatitis viruses?
The five main hepatitis viruses are hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV, delta virus), and hepatitis E virus (HEV).
How is Hepatitis A virus (HAV) transmitted?
HAV is transmitted by the fecal–oral route. Humans are the reservoir for HAV. The virus appears in the feces roughly 2 weeks before the appearance of symptoms.
What is the most important laboratory test for diagnosing acute Hepatitis A?
The detection of IgM antibody is the most important test for diagnosing acute Hepatitis A.
What are the three main modes of transmission for Hepatitis B virus (HBV)?
The three main modes of transmission for HBV are blood (including needle stick injury), sexual contact, and perinatally from mother to newborn.
What are the two most important serologic tests for the diagnosis of early Hepatitis B?
The two most important serologic tests for the diagnosis of early Hepatitis B are HBsAg and IgM antibody to the core antigen.
What does the presence of HBeAg indicate in Hepatitis B infection?
The presence of HBeAg indicates a high likelihood of transmissibility.
What is the significance of HBsAb in Hepatitis B infection?
HBsAb neutralizes the infectivity of HBV and provides lifelong immunity.
What is the treatment for chronic Hepatitis B?
For chronic Hepatitis B, nucleoside analogues that inhibit the reverse transcriptase of HBV are used. Interferon is also used.
What is the name of the vaccine that provides protection against both Hepatitis A and Hepatitis B?
The vaccine that provides protection against both Hepatitis A and Hepatitis B is called Twinrix.
What is the purpose of Hepatitis B immune globulin (HBIG)?
Hepatitis B immune globulin (HBIG) contains a high titer of HBsAb and is used to provide immediate, passive protection to individuals known to be exposed to HBsAg-positive blood (e.g., after an accidental needle-stick injury).
What is the significance of the ‘window phase’ in Hepatitis B serology?
The ‘window phase’ is a period of several weeks when HBsAg has disappeared but HBsAb is not yet detectable. At this time, the HBcAb is always positive and can be used to make the diagnosis.
What is the significance of prolonged presence of HBsAg in Hepatitis B infection?
The prolonged presence of HBsAg (at least 6 months) indicates the carrier state and the risk of chronic hepatitis and hepatic carcinoma.
