13 - Hepatitis Flashcards
What is hepatitis?
- Hepatitis is the inflammation of the liver due to cell injury or viruses (hepatotropic) which can cause collateral liver damage e.g. EBV, CMV, VZV
- Replicates in hepatocytes and destroys them
What are the different types of hepatitis and what are their modes of transmission and incubation periods?
Hep B and C cannot sort themselves out on their own
Outline the viral structure of Hep B and Hep C.
- Hepatitis B: dsDNA, enveloped
- Hepatitis C: ssRNA, positive, enveloped, icosahedral
How is bilirubin produced an excreted?
What are the different causes of jaundice and what causes each of these?
- Prehepatic – caused by haemolysis
- Intrahepatic – caused by viral hepatitis, drugs, alcohol hepatitis, cirrhosis
- Extrahepatic – caused by common duct stones and carcinoma
What are some liver function tests?
- Bilirubin
- ALT/AST (hepatocyte damage)
- ALP (biliary tract cell damage)
- Albumin
- Tests of coagulation as clotting factors produced in liver (INR and PT)
A patient has the following liver function tests, what type of jaundice does he have?
Intrahepatic
How can Hep B be transmitted?
- Vertical transmission
- Sexual contact
- Contaminateed needles (drug and needle stick injury)
- Blood exposure
- Close contacts, e.g sharing toothbrushes
What are the symptoms of acute Hep B?
- Jaundice
- Fatigue
- Abdominal pain
- Anorexia
- Nausea
- Vomiting
- Arthralgia
What are the microbiological findings of Acute Hep B?
- AST/ALT in 1000s
- Incubation: 6 weeks to 6 months so may get missed
What are the complications of acute Hep B?
- 50% no/vague symptoms and clears in 6 months
- 1% sudden hepatic failure
- Becomes chronic in 10% adults, 90% children
What are the different stages of serology for Hep B?
- HBsAb produced in response to HBsAg
- HBeAb produced in response to HBeAg
- IgM and IgG in response to HBcAG
(can look at HBV DNA in PCR but not serology)
What is the definition of a chronic Hep B infection?
Persistance of HBsAg after 6 months
- 25% will develop cirrhosis and 5% will develop hepatocellular carcinoma
If you see IgG for HepB in a patients blood what can this mean?
- May have had the infection and cleared it already or may be infected
What is the treatment for HepB?
- NO CURE
- Life long antivirals
- Not all people need antivirals as may be inactive carrier and have low viral load
What is the vaccination for Hep B?
- The vaccination consists of a genetically engineered surface antigen (3 doses + boosters if required)
- Produces surface antibody response:
I. >10 adequate
II. >100 long-term protection
What would each of the following scenarios look like with a hepatitis B case? (indicate if present or absent)
Who is at risk of Hep C transmission?
- IVDU
- Sexual contact (higher if HIV coinfected)
- Vertical transmission
- Blood transfusion before 1991
- Needle stick injuries
What is the disease progression of Hep C?
80% will become chronically infected
Of these some will develop chronic liver disease/cirrhosis, e.g HCC, decompensated liver disease
What are the symptoms of a Hep C infection?
OFTEN GO UNOTICED SO DANGEROUS
What are the complications of chronic liver disease/cirrhosis due to a chronic Hepatitis C infection?
- Decompensated liver disease
- Hepatocellular carcinoma (primary liver cancer)
- Transplant
- Death
What are the blood tests involved in diagnosing Hep C?
- Serology – anti-Hep C antibody as it remains positive throughout life, even after clearance/cure (not protective, can get reinfected)
- Viral PCR – if positive, confirms on-going / chronic infection
What is the treatment for Hep C?
- Cure but no vaccine
- Directly acting antiviral drug combo:
- 8-12 weeks, 90% chance of cure, £10,000 to £50,000 per couse and can get reinfected
Discuss the risk of transmission of HIV, Hep B and C from needlestick injury.
A medical student has a needle stick injury whilst taking blood from a known HIV positive man, what should be done?
- First aid: bleed and wash wound
- Collect blood from patient and med student
- Inform occupational health
- Check med students hep B vaccination status
- Immediate PEP
What should be done with HIV PEP?
- Early administration of ARV within 72 hours
- 3 a day for 28 days and then blood test at baseline, 1 month later, 3 months later
- Counselling to discuss how to prevent transmission
Distinguish between HIV, Hep B and Hep C in terms of:
- Acute infection
- Prevention
- Outcome of untreated infection
- Treatment
