Hepatitis A

Question 1

How many genotypes of HAV?

Answer 1

Three (I, II, III with subgenotypes IA, IB, IC, IIA, IIB, IIIA, IIIB)

Question 2

When is the highest risk of trasnmission of HAV?

Answer 2

In the prodromal phase prior to symtom onset, which lasts about one week

Question 3

Why is HAV so stable in the environmnet?

Answer 3

It can withstand, drying, low pH, detergents

Question 4

How long do symptoms persist in HAV infection?

Answer 4

2-8 weeks

Question 5

What percentage of adults and children have symptomatic HAV?

Answer 5

Adults >70%, children <30%

Question 6

What percetage of patients with HAV have relapsing hepatitis?

Answer 6

12% have relapsing hepatitis, 7% have prolonged cholestatis with pruritis and fatigue

Question 7

What are the 5 presentations of HAV?

Answer 7

1) Asymptomatic 2) Hepatitis (jaundice etc) 3) Cholestatic hepatitis 4) Relapsing hepatitis 5) Fulminant hepatitis

Question 8

What are symptoms of acute liver failure in HAV?

Answer 8

Rapid deterioration in liver function, hepatitic encephalopahty, loss of cognitiive brain fucntion, motor dysfunction

Question 9

What % of patients with acute liver failure from HAV recover?

Answer 9

70% recover spontaneously with conservative therapty (fluids treating hypoglycaemia and electrolyte imbalacne, Abx and rest) 30% require liver transplant

Question 10

What are the signs of severe acute liver failure?

Answer 10

Deterioration of hepatic systemic function - coagulopathy, reduced INR, rising creatinine, drop in serum albumin, rising blood ammonia and hepatitic encepahlopahty

Question 11

What are extra-hepatitic manifestations of HAV?

Answer 11

Acute kidney injury, cryoglobulinaemia, cholecysisits, pancreatitis, pleural effusion, pneumonitiis, haemolysis, rash, reactive arthrititis, neurological (mononeuritis, GBS, transverse myeltitis, neuritis)

Question 12

Who is at risk of severe disease with HAV?

Answer 12

1) Patients with chronic liver disease 2) Severely immunosuppressed 3) Elderly (>50 y!!)

Question 13

How long does viraemia and feacal shedding last in HAV infection?

Answer 13

Viraemia can last several months, faecel shedding can last for 6 months, and RNA detected in liver for up to 12 m

Question 14

Is HAV IgM likely to be positive at onset of symptoms?

Answer 14

Can be falsely negative if collected <5 days post symptom onset

Question 15

What region of the HAV genome is used for RT-PCR and what is used for genotyping?

Answer 15

PCR = 5’ NCR and genotyping = VP1-pX

Question 16

What type of HAV vaccines are available in the UK?

Answer 16

Inactivated, either monovalent or combined with HBV or typhoid

Question 17

Vaccine schedule for HAV vaccine

Answer 17

Primary dose gives 1 years protection, 2 doses 6-12 m apart >25 y immunity

Question 18

What age is HAV vaccine licensed for?

Answer 18

Over 1 year

Question 19

What is the antibody titre conisidered immune post HAV vaccine

Answer 19

20 mIU/ml

Question 20

What are Havrix, Avaxim and Vaqta?

Answer 20

Monovalent HAV vaccines

Question 21

What are Twinrix and Ambirix?

Answer 21

HAV and HBV dual vaccine

Question 22

What does ViATIM vaccine protect against?

Answer 22

HAV and typhoid

Question 23

Who would get HAV vaccine as pre-exposure prophylaxis?

Answer 23

Travellers, severe or chronic illness, haemophiliacs, MSM, PWID, lab workers, sewage workers, staff and residents at large residential institutions, people working with primates. Consider in: healthcare workers, staff at daycare facilities, food handlers

Question 24

How effective is HNIG as PEP following HAV exposure?

Answer 24

80-90% effective if administered within 14 days

Question 25

How long does HNIG last as passive immunisation for HAV?

Answer 25

4-6 months

Question 26

How long must you wait between giving HNIG or HBIG and administering a live vaccine?

Answer 26

3 months

Question 27

When would you test for HAV IgG in a contact?

Answer 27

To avoid giving HNIG unneccessarily - and only if you can get a result within 3 days and within the PEP window (either post contact or within 7 days of vaccine)

Question 28

What is the infectious period of HAV?

Answer 28

2 weeks prior to first symptoms until 1 week post jaundice (or other symptoms if no jaundice)

Question 29

Who would be considered immune post HAV contact? And what PEP would you consider?

Answer 29

Patients with 1) previous lab confirmed HAV infection, 2) 2 vaccines in the last 10 years 3) 1 vaccine in the last 12 months. No PEP

Question 30

Who would be considered 'primed' post HAV contact? And what PEP would you consider?

Answer 30

Patients with 1) 2 vaccines >10 years ago 2) 1 vaccine >12 months ago. Vaccine only, no HNIG

Question 31

How would you manage the index case of HAV outbreak?

Answer 31

Advise good hand hygeine! Exclude for 7 days from onset of jaundice, identify possible source, risk assessment and questionnaire

Question 32

If a patient is vaccinated for HAV as a contact, can you still administer HNIG?

Answer 32

Yes, but only within 7 days of vaccine

Question 33

HAV PEP for healthy 1-59 year olds

Answer 33

Within 14 d: vaccine only. After 14 d: vaccinate up to 8 weeks post exposure only if >1 case in household

Question 34

HAV PEP for healthy <1 year old identified within 14 days

Answer 34

Not at nursery: vaccinate nappy changers. At nursery: vaccinate if >2 months

Question 35

PEP for healthly 1 year old identified >14 days post contact

Answer 35

Reinforce hygeine, if not possible, exclude for 30 days. If unable to exclude, vaccinate all contacts at nursery aged >2 months

Question 36

HAV PEP for >60 year olds

Answer 36

Vaccine and HNIG (within 14 days)

Question 37

HAV PEP for immunosuppressed contacts

Answer 37

Vaccine and HNIG (within 14 days)

Question 38

HAV PEP for patients with chronic liver disease

Answer 38

Vaccine and HNIG (within 28 days)

Question 39

HAV PEP for food handler

Answer 39

Within 14 days: vaccinate. >14 days: move duties til 30 days post exposure

Question 40

Which groups of people are at increased risk of spreading HAV?

Answer 40

A) People with doubfful personal hygeine B) All <5 years who atttend childcare C) Food handlers D) Clinical and social care staff

Question 41

What vaccine coverage is required to disrupt transmission in a HAV outbreak?

Answer 41

40% vaccine coverage (assuming an R0 of 1.6)

Question 42

Why should haemophiliacs be vaccinated against HAV?

Answer 42

HAV transmission has been associated with Factor VIII and IX, as HAV can withstand the inactivation process

Question 43

Hep A incubation period

Answer 43

28 days, with a range of 15–50 days.

Question 44

Hep A infectious period

Answer 44

2 weeks before to one week after onset of dark urine/jaundice/symptoms