Hepatitis A

Question 1

Is Hep A nationally notifiable?

Answer 1

Yes - urgent, labs and doctors

Question 2

Which organism causes Hep A?

Answer 2

Hepatitis A virus - single serotype (6 genotypes - 3 in humans)

Resistant to low pH, heat, freezing temps. Persistent in faeces, water, soil.

Question 3

How is Hep A transmitted?

Answer 3

Faecal-oral:
* Food - contaminated, not cooked further
* Water e.g. untreated bore water
* Fomites
* Sexual activity e.g. analingus

Question 4

What are the clinical features of Hep A?

Answer 4

• Asx (usu. young children)
• Prodrome (fever, malaise, anorexia, nausea, abdo pain)
• Progress to jaundice, dark urine, pale stools few days later

Usually self-limiting (1-3 weeks). Complications rare.

Young children ASx or mild GI sx

Question 5

Which groups are at high risk for severe Hep A disease?

Answer 5

• > 50yo
• Immunosuppressed
• CLD

Question 6

Which groups are at high risk of Hep A acquisition?

Answer 6

FNs, travellers to endemic countries, MSM, PWID, prisoners, people experiencing homelessness, childcare workers

Question 7

What are case definitions for Hep A?

Answer 7

Confirmed:
* PCR
* IgM + clinical/epi

Probable:
* Clinical + epi

Question 8

How is Hep A diagnosed?

Answer 8

PCR or serology (IgM).

Confirmatory testing and WGS at VIDRL.

Question 9

What is the incubation period for Hep A?

Answer 9

15 - 50 days
(usually 28-30)

Question 10

What is the infectious period for Hep A?

Answer 10

2 weeks prior to sx onset until 1 week after jaundice onset.

Continue good hygiene and precautions after this time.

Question 11

Where are most Hep A cases acquired?

Answer 11

Overseas but large outbreaks have occurred in Australia (contaminated food, MSM) and smaller local outbreaks e.g. childcare.

Question 12

What is the outbreak definition for Hep A?

Answer 12

2 + related cases depending on setting

Question 13

What is the cluster definition for Hep A?

Answer 13

Increase in cases by TPP or genomic with unknown common source.

Question 14

How long does immunity to Hep A last?

Answer 14

Lifelong

Question 15

How is Hep A prevented?

Answer 15

Vaccination - Hep A vaccine (2 doses)
Hygienic food handling
Precautions while travelling
General hygiene

Question 16

For which groups is Hep A vaccination on the NIPS?

Answer 16

FNs children in NT, QLD, SA, WA (18mo and 4y)

Question 17

For which groups is Hep A vaccination recommended?

Answer 17

• CLD
• Developmental disability + carers
• Travelers to endemic countries
• Childcare staff
• Plumbers
• Sex workers
• Remote indigenous communities
• MSM
• PWID
• Prisoners

Question 18

What resources are available for public health management of Hep A?

Answer 18

SoNG, DH protocol

Question 19

How are Hep A cases managed?

Answer 19

Clinician interview
Case interview - DRSVECTA - inc. travel, sex, food, sewage, drugs, high-risk settings, contacts
T - treating clinician (usu. self-limiting)
I - exclusion: primary school / ECEC, food handlers, childcare workers for 7d following jaundice onset; restriction: no food prep / personal care / sharing utensils, towels etc while infectious
E - sx, transmission, hygiene, cleaning advice

Question 20

Which cases require thorough risk assessment?

Answer 20

Food handers - ready to eat vs. cooked food, hygiene, cleaning, training

May need site visit

Question 21

Who are considered Hep A contacts?

Answer 21

• HH / HH-like
• Sexual
• Consumed ready to eat food made by case
• Provided direct care if case in nappies, same childcare/preschool room

Question 22

How are Hep A contacts managed?

Answer 22

T - PEP (vaccine dose or NHIG) withing 2 weeks of last exposure without past infection/immunisation.
* Usually vax aged 1-40 and > 40 require risk assessment
* NHIG - under 1yr or vaccine contraindications

Question 23

Which groups require exclusion?

Answer 23

• Primary / ECEC
• Food handlers
• HCW
• Childcare workers

Contacts do not requrie exclusion

Question 24

For how long should cases be excluded?

Answer 24

Until 7 days after jaundice onset.

Question 25

For how long should contacts be excluded?

Answer 25

Nil required.

Question 26

What environmental management is required?

Answer 26

* Cleaning - esp. childcare, food premises * Food/water sampling * Source identification in outbreak (may need analytic study)