GIS26 Viral hepatitis, serological tests and immunization

Question 1

Name 3 modes of spread of HEV.

Answer 1

1. Fecal-oral
   - crowding / poor sanitation
   - high mortality in pregnant women infected in the 3rd trimester
2. Foodborne
   - undercooked, pig-liver congee
3. Parenteral: blood transfusion / Organ transplant
4. Rodents
   - environmental / food contamination by excreta?
   esp. chronic hepatitis after liver transplant

Question 2

From 2020-2022, by the number of reported cases in Hong Kong, which hepatitis virus is the greatest contributor?

Answer 2

HEV

Question 3

What enables prolonged viability of HEV outside the body?

Answer 3

Tough outer capsid

Note:
non-enveloped => higher resistance to disinfection

Question 4

How to diagnose hepatitis E?

Answer 4

Acute: HEV IgM
Chronic: HEV RT-PCR

HEV RNA in blood first => later also found in faeces

Question 5

What is the usual duration of incubation period of HEV?

Answer 5

2-6 weeks
Usually >4 weeks

Question 6

Name 3 groups of individuals susceptible to chronic hepatitis E.

Answer 6

1. Transplant recipients
2. Patients receiving chemotherapy
3. HIV +ve patients

Question 7

Name 3 groups of individuals who may experience more severe acute hepatitis E.

Answer 7

1. Pregnant women
2. Elderly
3. Underlying chronic liver disease

Question 8

Name the treatments for different stages of hepatitis E.

Answer 8

Acute: supportive care
Fulminant: liver transplant
Chronic: reduce immunosuppression, oral ribavirin

Question 9

Which hepatitis viruses are vaccine preventable?

Answer 9

HAV, HBV
HEV (Hecolin, mainland China only)

Question 10

Name three other causes of viral hepatitis except the Big Five.

Answer 10

Cytomegalovirus
Primary EBV
Primary HHV-6
Adenovirus
Enterovirus
Part of many other viral syndromes e.g. SARS => systemic inflammation

Question 11

Name 3 symptoms of viral hepatitis.

Answer 11

Jaundice, dark urine, pale stools
Abdominal pain
Vomiting, diarrhoea, loss of appetite
Fatigue

Question 12

Name 3 basic blood tests for viral hepatitis.

Answer 12

1. Bilirubin
2. Hepatic transaminases: AST, ALT
3. Clotting profile (increase)
4. Albumin (decrease)

Question 13

Name 2 modes of spread of HAV.

Answer 13

1. Faecal-oral
2. Food-borne
   - contaminated shellfish, seafood
3. Direct contact
4. MSM, IV drug users, blood transfusion (rare)

Question 14

Which family does HAV belong to?

Answer 14

Picornaviridae

Question 15

Why does HAV have good environmental survival?

Answer 15

Non-enveloped

Question 16

Excess envelope of HBV is used to form subviral … particles in … or … shape.

Answer 16

Lipoprotein
Spherical
Filamentous

Question 17

Describe HBV replication cycle.

Answer 17

Cell entry via NTCP
Migration of core to nucleus
Completion of double strand: rcDNA -> cccDNA
Transcription of cccDNA
Translation of viral proteins, reverse transcription of pgRNA to genomic DNA
Generation of positive strand
Packaging of mature virus
Virus budding

Question 18

Modes of transmission of HBV

Answer 18

BBB

Blood & Body fluid (RARE in healthcare workers & blood transfusion)
*** Birth (perinatal), Breast feeding
Banging (sexual)