Viral Hepatitis Flashcards
Which hepatitis virus is a double-stranded DNA hepadnavirus?
Hepatitis B
How is Hepatitis B spread?
Spread through exposure to infected blood or bodily fluids
Vertical transmission form mother to child.
What is the incubation period of hepatitis B?
6-20 weeks
What are the features of Hepatitis B?
- Fever
- Jaundice
- Elevated liver transaminases.
What are some complications of hepatitis B infection?
- Chronic hepatitis (5-10%)
- Fulminant liver failure (1%)
- Hepatocellular carcinoma
- Glomerulonephritis
- Polyarteritis nodosa
- Cryoglobulinaemia
For hepatitis B, how many vaccinations are given and then how long until another booster is given?
3 doses of the vaccine are given and the booster is then given 5 years after the first vaccination.
(It is not routine and mainly if you are having exposure prone procedures)
What at risk groups should be vaccinated for Hep B?
- Healthcare workers
- IV drug users
- Sex workers
- Close family contacts of an individual with Hep B
- CKD patient who may soon require dialysis.
- Prisoners
- Chronic liver disease
What percentage of adults fail to respond to the vaccine and why?
10-15%
Due to obesity, alcohol excess, smoking or immunosuppression.
When would you test for anti-Hbs levels?
- Healthcare workers doing risk prone procedures.
- CKD
Anti-Hbs levels should be checked 1-4 months after primary immunisation.
How do you interpret anti-HBs levels?
- >100 - adequate response - no further testing required.
- 10-100 - suboptimal response - one additional vaccine dose needed.
- <10- non responder. Test for current or past infection. Give further vaccine course (3 doses). If still fails to respond then HBIG would be required for protection if exposed to the virus.
What is the management of Hepatitis B?
- Pegylated interferon-alpha used to be the only treatment available. It reduces viral replication in up to 30% of chronic carriers. A better response is predicted by being female, < 50 years old, low HBV DNA levels, non-Asian, HIV negative, high degree of inflammation on liver biopsy
- Whilst NICE still advocate the use of pegylated interferon firstl-line other antiviral medications are increasingly used with an aim to suppress viral replication (not in a dissimilar way to treating HIV patients)
- Examples include tenofovir and entecavir
What is HBsAg?
- HBsAg is Surface antigen
- It is the first marker to appear and causes the production of Anti-HBs
-
HBsAg normally implies acute disease (present for 1-6 months)
- if HBsAg is present for > 6 months then this implies chronic disease (i.e. Infective)
What does Anti-HBs imply?
Anti-HBs implies immunity (either exposure or immunisation). It is negative in chronic disease
What does Anti-HBc imply?
- REMEMBER: Anti-HBc = “caught”
- Anti-HBc implies previous (or current) infection.
- IgM anti-HBc = acute infection and is present for about 6 months.
- IgG anti-HBc = past infection.
What does HbeAg imply?
HbeAg results from breakdown of core antigen from infected liver cells as is therefore a marker of infectivity/transmissibility.
What hepatitis virus is an RNA flavivirus?
Hepatitis C
What is the incubation period for hepatitis C?
6-9 weeks
Is breast feeding contraindicated in mothers with hepatitis C?
No.
How is hepatitis C transmitted?
Mostly through injecting illegal drugs.
Less commonly: Unprotected sex, blood transfusions, vertical transmission.
Is hepatitis B more an acute or chronic disease?
Chronic.
20% will develop acute hepatitis. 80-85% will develop a chronic infection.
What are some complications of hepatitis C?
- Cirrhosis (20-30% of those with chronic disease)
- Hepatocellular cancer
- Cryoglobulinaemia
- Porphyria cutanea tarda (PCT): it is increasingly recognised that PCT may develop in patients with hepatitis C, especially if there are other factors such as alcohol abuse
What is the management of Chronic hepatitis C infection?
- Currently a combination of pegylated interferon-alpha, ribavirin and a protease inhibitor (e.g. boceprevir or telaprevir) is used.
- Up to 55% of patients successfully clear the virus, with success rates of around 80% for some strains
- The aim of treatment is sustained virological response (SVR), defined as undetectable serum HCV RNA six months after the end of therapy
What are some side effects of ribavirin?
- Haemolytic anaemia
- Cough
- Teratogenic - Women should not become pregnant within 6 months of stopping ribavririn.
What are some side effects of pegylated interferon alpha?
- Flu-like symptoms
- Depression
- Fatigue
- Leukopenia
- Thrombocytopenia
Is breastfeeding contraindicated in hepatitis B & C?
No
Hep B cannot be transmitted this way & Hep C has very low chance of verticla transmission this way.
What should all babies receive who are born to mothers with acute hepatitis B during pregnancy?
Complete vaccination course and hepatitis B immunoglobulin (HbIg)
Except if the patient had antibodies against HBe (anti-HBe) - then only the vaccination is required.
Does C-Section reduce vertical transmission rates?
No
HBsAg negative
anti-Hbc negative
anti-Hbs negative
Susceptible
HBsAg negative
anti-Hbc positive
anti-Hbs positive
Immune due to previous infection but no longer has hepatitis B.
HBsAg negative
anti-Hbc negative
anti-Hbs positive
Immune due to Hepatitis B Vaccination
HBsAg positive
anti-Hbc positive
IgM anti-Hbc positive
anti-HBs negative
Acutely infected
HBsAg positive
anti-Hbc positive
IgM anti-Hbc negative
anti-HBs negative
Chronically infected
(In this case IgG anti-HBc would confirm this and be present)
HBsAg negative
anti-Hbc positive
anti-HBs negative
Interpretation unclear
Most likely
- Resolved infection (most likely)
- False-positive anti-HBc, thus susceptible.
- Low level chronic infection
- Resolving acute infection