Viral Hepatitis

Question 1

What is the definition of acute and chronic hepatitis

Answer 1

Acute - Usually symptomatic with deranged LFTs (raised ALT and AST)
Chronic - When hepatitis virus presents for more than 6 months. Usually is asymptomatic

Question 2

What are the routes of transmission for the different hepatitis viruses

Answer 2

A and E - Faecal oral route
B, C and D - Blood borne

Question 3

What are the infectious and non infectious causes of acute hepatitis?

Answer 3

Infectious - Hepatitis viruses, EBV, CMV, toxoplasmosis, leptospirosis, Q fever, syphilis, malaria.
Non infectious m- Toxins, drugs, alcohol, autoimmune, Wilsons and haemochromatosis

Question 4

What are the different laboratory diagnostic techniques for viral hepatitis?

Answer 4

Direct detection of the immune response via IgM or IgG.
Viral nucleic acid detection (RNA or DNA) or antigen detection (HBV and HCV)

Question 5

What are the features of Hepatitis A?

Answer 5

RNA virus transmitted via faeco-oral route. Incubation period is 2-4 weeks. NO chronic carriage.
Age is the main determinant of severity. Most children are asymptomatic.
Self limiting illness with no treatments however good immunity after infection/vaccination

Question 6

Explain the diagnosis of hepatitis A

Answer 6

In an acute infection patient will be IgM positive or have HAV RNA in blood/stool.
IN a previous hep A/vaccinated patient IgG will be detected
IgM and/or IgG against HAV

Question 7

Describe features of the hepatitis A vaccine

Answer 7

• Inactivated virus which gives life long immunity after 2 doeses. Given to travellers, MSM, IVDU or chronic liver diseases.

Question 8

When is hepatitis A immune globulin used?

Answer 8

If patient is vaccine allergic or if there is less than 4 weeks till travel. It offers 3-6 months of immunity. It is pooled immunoglobulin

Question 9

Describe features of hepatitis E

Answer 9

RNA virus transmission occurs via faeco-oral route or contaminated pork products. Incubation period is 40days. 4 genotypes with most common being GT3.
Treatment is supportive, no vaccine and chronic hep E only in immunocompromised High mortality in pregnancy

Question 10

What are the complications of a Hepatitis E infection?

Answer 10

Neurological complications which are associated with genotype 3. These include:
- Guilliane barre syndrome,
- Encephalitis,
- Ataxia,
- Myopathy

Question 11

Describe features of hepatitis B and its routes of transmission

Answer 11

DNA virus which causes around 2million deaths per year. However is vaccine preventable.
Transmission occurs via - Mother to baby (most common), contaminated needles/syringes, child to child, organs and tissue transplants, bodily fluids or transfusion of blood products.

Question 12

Describe features of acute hepatitis B infections

Answer 12

Incubation is 2-6months. Age at time of infection determines severity and risk of developing chronic hepatitis B. Infection at young age is likely to be asymptomatic but high risk of chronic. Infection at old age is likely to be symptomatic but not chronic

Question 13

What are the complications of a hepatitis B infection

Answer 13

Chronic HBV which can cause:
- Cirrhosis,
- Decompensation,
- Hepatocellular carcinoma (can present with weight loss, abdo pain, fever, cachexia, bloody ascites, jaundice),
- Death

Question 14

What are the laboratory tests in hepatitis B?

Answer 14

sAg (surface antigen) - marker of active infection.
sAb (Surface antibody) - marker of immunity.
cAb (core antibody) - present in anyone who has had active infection, negative in vaccination.
eAg (e antigen) suggests high infectivity.
eAb (e antibody) suggests low infectivity.

Question 15

What are the two groups of chronic hepatitis B infections

Answer 15

eAg positive (early disease) - there will be a high viral load, high risk of chronic liver diseases and hepatocellar carcinoma and highly infectious.
eAg negative (late disease) - there will be low viral load, lower risk of CLD/HCC and less infectious.

Question 16

What is the treatment for acute hepatitis B?

Answer 16

None. Infection usually resolves on its own

Question 17

What is the treatment for chronic hepatitis B?

Answer 17

• None unless patients shows liver inflammation or fibrosis. In which case treatment is suppression of viral replication via: interferon (immuno-modulatory) or tenofovir/entecavir (Supress viral replication)

Question 18

What are the prevention methods for hepatitis B?

Answer 18

• Education,
• Immunisation (HBV sAg vaccine)
• Prevention of mother to child transmission. If mother is positive then baby is given HBV vaccine in first 24hours of life and 6 total in first year. If mum has high viral load then given HBV immunoglobulin (if eAg +) or tenofovir in 3rd trimester.

Question 19

Describe features of hepatitis D

Answer 19

Can only be acquired if co-infected with HBV sAg positive, as HDV requires HBV to replicate.
Infection increases risk of chronic liver disease. Treatment is via interferon only (bulevirtide maybe)

Question 19

Describe features of hepatitis C

Answer 19

• RNA virus transmitted via injecting drugs, transfusions/transplants and rarely sexual.
  There is no reliable immunity after infection, no vaccine or prophylaxis.
• Incubation is 6-7 weeks. Around 30% clear the infection and 70% go on to develop chronic infections.

Question 20

Explain the diagnosis of hepatitis C

Answer 20

• Most diagnoses occur by screening high risk groups (IVDU or immigrants)
• Anti HCV IgG positive means chronic infection or cleared infection. Whereas PCR or antigen positive means a current infection.

Question 21

Explain the treatment of hepatitis C

Answer 21

Direct Acting Antivirals (DAAs) inhibit different stages of the replication cycle. Can cure almost everyone within 8-12 weeks of oral treatment.
Regimen of treatment is according to genotype and degree of cirrhosis.