Lecture 8.1: Viral Hepatitis

Question 1

What is Hepatitis?

Answer 1

It is a general term referring to inflammation of the liver

Question 2

Causes of Hepatitis: Infectious (4)

Answer 2

• Viral
• Bacterial
• Fungal
• Parasitic

Question 3

Causes of Hepatitis: Non-Infectious (7)

Answer 3

• Alcohol
• Drugs
• Chemical
• Autoimmune
• Metabolic Diseases
• Genetic
• Radiation

Question 4

Signs & Symptoms of Hepatitis (11)

Answer 4

• Fever
• Malaise
• Upper Abdominal Discomfort/ RUQ tenderness
• Jaundice
• Development of Ascites (very uncommon)
• Oedema (very uncommon)
• Spider Naevi
• Mild Hepatomegaly
• Splenomegaly
• Persistent Nausea & Vomiting
• Hepatic Encephalopathy (in severe cases,
suggests liver failure)

Question 5

What are the most common causes of Viral Hepatitis?

Answer 5

5 unrelated hepatotropic viruses:
• Hep A
• Hep B
• Hep C
• Hep D
• Hep E

Question 6

What are some other viruses that can cause liver inflammation? (3)

Answer 6

• Cytomegalovirus
• Epstein–Barr Virus
• Yellow Fever

Question 7

Hepatitis A Virus: Structure

Answer 7

• Naked RNA virus (naked icosahedral capsid, single-stranded RNA genome)
• Only 1 stable serotype
• 4 genotypes exist, but in practice most of them are group 1

Question 8

Hepatitis A Virus: Transmission Types

Answer 8

• Close Personal Contact
• Contaminated Food
• Contaminated Water
• Blood Exposure (rare)

Question 9

How does Hepatitis A invade the human body?

Answer 9

• Faecal-Oral Route
• Multiplies in the Intestinal Epithelium
• Reaches the Liver by Haematogenous spread

Question 10

What is the Incubation period of Hepatitis A?

Answer 10

2 to 6 weeks

Question 11

Diagnosis of Hepatitis A (8)

Answer 11

• Examination of Patient
• Patient History
• Complete Blood Count
• Biochemical Blood Test
• Coagulogram
• Liver Function Test
• Viral Hep Marker Analysis
• Urine and Faeces Analysis

Question 12

Hepatitis E Virus Structure

Answer 12

• Calicivirus-like viruses
• Unenveloped RNA virus
• 32-34nm in diameter
• Positive stranded RNA genome (7.6 kb in size)
• Very labile and sensitive

Question 13

Transmission of Hepatitis E

Answer 13

• Eating Raw Shellfish
• Sexual Contact
• Use of Non-Sterile Syringes
• Consumption of Contaminated Food and Water
• Swimming in Dirty Water
• Contact with Sick People

Question 14

Hepatitis B Virus Structure

Answer 14

• It is a double-stranded DNA hepadnavirus
• The whole virus is called the Dane particle
• Replication involves a reverse transcriptase
• 42nm enveloped virus
• 22nm spheres and filaments other forms- no DNA in these forms so they are
not infectious (composed of surface antigen)
• These forms outnumber the actual virions

Question 15

Can you culture Hep B

Answer 15

Not yet

Question 16

HBV Antigens

Answer 16

HBsAg = surface (coat) protein ( 4 phenotypes : adw, adr, ayw and ayr)
HBcAg = inner core protein (a single serotype)
HBeAG = e antigen; an indicator of transmissibility
(minor component of the core- antigenically
distinct from HBcAg) secreted protein; function
unknown

Question 17

Transmission of Hepatitis B (7)

Answer 17

• Sexual Contact
• Blood Transfusions
• Re-use of contaminated needles and syringes
• Through wounds/insect bites/animal bites
• From mother to child (MTCT) during childbirth
• Intrauterine (through placenta)
• Breastfeeding

Question 18

Hepatitis B: Mechanism of Invasion

Answer 18

• Virus enters hepatocytes via blood
• RNA intermediate: HBV replicates through an RNA intermediate
• This produces and release antigenic decoy particles
• Reverse transcription: mRNAs is converted into the DNA
• This DNA will eventually be the core of the progeny virion
• Integration: Some DNA integrates into host genome causing carrier state

Question 19

Hep B Decoy Particles: What are they? Importance?

Answer 19

• HBsAg-containing particles are released into the serum of infected peopl
• These outnumber the actual virions
• Spherical or filamentous
• They are immunogenic
• Were processed into the first commercial vaccine against HBV.

Question 20

Diagnosis of Hepatitis B

Answer 20

• Examination of Patient
• Patient History
• Complete Blood Count
• Biochemical Blood Test
• Liver Function Test
• Viral Hep Marker Analysis
• Ultrasonography of Abdomen

Question 21

Importance of HBeAg in HBV

Answer 21

Hepatitis B e antigen (HBeAg) is an indicator of viral replication

Question 22

Importance of HBsAg and HBsAb in HBV

Answer 22

HBsAg - used as a general marker of infection

HBsAb - used to document recovery and/or immunity to HBV infection

Question 23

Importance of Serum anti HBc

Answer 23

It is most useful & inexpensive marker for identification of occult HBV infection in HBsAg negative individuals

Question 24

What is an Occult HBV Infection?

Answer 24

• Presence of HBV DNA in the liver
• Detectable (< 200 IU/ml)
• Undetectable HBV DNA in serum
• HBs Ag negative
• Anti HBc antibodies

Question 25

Hepatitis D (Delta) Virus Structure

Answer 25

• Virion: spherical, 36-38 nm, • HBV capsid, HDV nucleoprotein • Delta antigen • HBsAg • Nucleic Acid: (-) ss RNA, circular • Satellite virus : replicates only in the presence of HBV

Question 26

When can Hep D be contracted?

Answer 26

You can only contract this is you are also currently suffering from Hepatitis B

Question 27

Consequences of Hepatitis B & Delta Virus Infection: Co-Infection

Answer 27

• Co-Infection • Severe acute disease • Low risk of chronic infection

Question 28

Consequences of Hepatitis B & Delta Virus Infection: Superinfection

Answer 28

• Usually develop chronic HDV infection • High risk of severe chronic liver disease • May present as an acute hepatitis

Question 29

Hepatitis C Structure

Answer 29

• Hepatitis C virus (HCV) is a single-stranded RNA flavivirus • Envelope • Envelope Proteins (E1 & E2) • Nucleocapsid • RNA

Question 30

Transmission of Hepatitis C (7)

Answer 30

• Sexual Contact • Blood Transfusions • During Operations • Re-use of contaminated needles and syringes • From mother to child (MTCT) during childbirth • Intrauterine (through placenta) • As a consequence of Infectious/Bacterial Infection Complications

Question 31

Signs & Symptoms of Hep C: Acute Infection (7)

Answer 31

• Decreased Appetite • Fatigue • Nausea • Muscle or Joint Pains • Weight Loss • Acute Liver Failure (rare) • Jaundice

Question 32

Signs & Symptoms of Hep C: Chronic Infection

Answer 32

• Fatigue • Mild Cognitive Problems • Fatty Liver • Cirrhosis • Hepatocellular Carcinoma • Ascites • Easy Bruising/Bleeding • Varices (enlarged veins) • Hepatic Encephalopathy

Question 33

What is the Incubation Period of Hep C?

Answer 33

1-26 weeks

Question 34

Stages of Liver in Acute Hepatitis (3)

Answer 34

Healthy Liver Acute Hepatitis Recovered Liver

Question 35

Stages of Liver in Chronic Hepatitis (4)

Answer 35

Healthy Liver Chronic Hepatitis Liver Cirrhosis Liver Cancer (hepatocellular carcinoma)

Question 36

How many Acute HCV turn into Chronic HCV?

Answer 36

C. 85%

Question 37

Treatment of Hep C

Answer 37

• Combination of pegylated interferon alpha and the antiviral drug ribavirin for. period of 24 or 48 weeks • Hepatitis C is a common reason for liver transplant • Ribavirin

Question 38

What are 5- of the many- Functions of the Liver? (9)

Answer 38

• URH • Bile Production • Filtering of Toxins • Excretion of bilirubin cholesterol, hormones, and drugs • Breakdown of carbohydrates, fats, and proteins • Activation of enzymes • Storage of glycogen, minerals, and vitamins (A, D, E, and K) • Synthesis of blood proteins • Synthesis of clotting factors