Hepatitis Flashcards
what is the incubation period for hepatitis B
40 days - 160 days
Describe the hepatitis B virus
Hepatitis B is a circular, partially double stranded DNA virus.
how can people catch Hepatitis B
Vertically : mother to baby
blood borne virus - needle stick injury, IVDUs sharing needles, sex, infected blood products/contaminated health care equipment (this is very rare in the UK)
what is the leading cause of hepatitis worldwide?
Hepatitis B
what are the consequence of chronic hepatitis B
HCC (hepatocellular carcinoma) and liver cirrhosis –> Acute liver failure
what proportion of patients with acute hepatitis B infection will be asymptomatic?
up to 50% of patients
Patients with acute hepatitis B - how many will go on to develop chronic hepatitis B (adults)
9/10 patients with acute hepatitis B will clear the virus without treatment. This is only true of adults.
Infants and children infected at birth - the majority will go on to develop chronic hepatitis B
what is the first serological marker that appears in acute hepatitis B infection
HBsAg
how is chronic hepatitis B defined serologically?
HBsAg presence for >= 6 months
A patient has Anti-HBs +ve. Does this mean they have previously had the hepatitis B vaccine or past infection? how would you investigate further
The presence of anti-HBs implies immunity to hepatitis B either by vaccination or previous cleared infection. In order to work this out request anti-HBc - if this is positive then implies previous cleared infection,
what is the difference between Anti-HBc IgM and anti- HBc IgG
IgM antibody is present in acute infection and over time is gradually replaced by IgG which represents past infection.
what does the presence of HBeAg indicate
HBeAg can be present in acute and chronic infection. It is a marker of infectivity and implies high HBV viral load therefore suggests high risk of transmission.
A patient has the following hepatitis serology, how would you define it?
HBsAg +ve, HBeAg +ve, anti-HBc IgM +ve, HBV DNA present
acute infection - highly infectious
A patient has the following hepatitis serology, how would you define it?
HBsAg +ve, HBeAg +ve, anti-HBc IgG +ve, HBV DNA high
chronic infection (active)
A patient has the following hepatitis serology, how would you define it?
HBsAg +ve, anti-HBe +ve, anti-HBc +ve (IgG), HBV dna low
chronic infection (inactive)