Hepatitis B

Question 1

Is Hep B nationally notifiable?

Answer 1

Yes.

Routine - labs, doctors.

Question 2

Which organism causes Hep B disease?

Answer 2

Hepatitis B virus.

8 genotypes (A-H)

Question 3

How is hep B transmitted?

Answer 3

Sexual (vaginal fluid, semen), blood-borne,

Parenteral, percutaneous or mucosal exposure to infectious body fluids.

Perinatal, needle-sharing, needle-stick injury, transfusion, medical/dental procedures, human bites, blood splash on mucous membranes, household transmission (mode unclear - more likely in crowded conditions)

Question 4

What are the clinical features of Hep B?

Answer 4

Spectrum: Asx (50-70% adults; 90% children), anorexia, fever, jaundice, malaise, N/V.

Acute liver failure < 1%.
Chronic infection (HBsAg > 6mo) in 5% adults, 95% neonates, 20-30% young children.
Usually ASx until signs of cirrhosis, HCC develop.

Question 5

Who are high-risk groups for hep B?

Answer 5

Acute: infants/mothers with HBV, HH contacts, sexual contacts, needle-sharing / other skin penetrating procedures, high risk occupations e.g. HCW

Chronic: people from high prevalence countries, FNs, infants of mothers with HBV, HIV/Hep C, prisoners

Question 6

How is Hep B diagnosed?

Answer 6

Serology (HBsAg) and/or HBV DNA.
Anti-HBc IgM = acute

VIDRL reference lab

Question 7

What is the incubation period for Hep B?

Answer 7

45-180 days
(commonly 60-90 days)

Question 8

What is the infectious period for Hep B?

Answer 8

Acute: several weeks before symptom onset for 4-5 months.
Chronic: infectious for life.

All people with HBsAg are potentially infectious; those with detectable HBV DNA highly infectious.

Question 9

Has the incidence of Hep B increased or decreased?

Answer 9

Decreasing since universal infant vaccination began in 2000.

Question 10

What proportion of people with chronic HBV are CALD or Indigenous?

Answer 10

72% - likely acquired at birth/in childhood

Question 11

What are the main modes of transmission of Hep B in Aus?

Answer 11

IVDU, sexual, vertical, household, skin-penetrating procedures.

Question 12

What are case definitions for Hep B?

Answer 12

Newly acquired:
HBsAg + and - in last 24 months OR
HBsAg + IgM OR
HBV DNA + IgM

Unspecified: HBsAg or HBV DNA

Question 13

How is Hep B prevented?

Answer 13

Vaccination - NIPS birth, 2, 4, 6, months; recommended for non-immune FNs, adults with HIV, haemodialysis, transplants, CDL/hepC, recurrent transfusions, HCW/other occupational risk, HH contacts, MSM, migrants from endemic countried, PWID, prisoners, sex workers, some travellers

Screening - donated blood / tissues, antenatal screening, screening other at-risk groups

Other: HBV vaccine and HBIG for infants of mothers with HBV, IPC in HC, health promotion: safe sex, needle-syringe programs, opioid substitution

Question 14

What resources are available for public health action for Hep B?

Answer 14

SoNG. DH guideline. ASHM guidance

Question 15

How are cases of Hep B managed?

Answer 15

T - antivirals to slow progrssion, test for coinfection with HCV, HDV, HIV; exposure Ix for newly acquired; ID RFs, others who may be at risk
I - EPPs for HCWs (viral load < 200IU/mL)
E - preventing transmission - safe injecting, safe sex, blood/body fluid precautions, not donating blood

Question 16

How are HCWs with Hep B managed?

Answer 16

National guidelines. Viral load < 200IU/mL, regular viral load monitoring to do EPPs.

Consider lookback if EPPs done while infectious.

EPP = exposure prone procedure

Question 17

How are contacts of HBV managed?

Answer 17

T - PEP - HBIG within 72hrs (e.g. perinatal, needle-stick, sexual contact); vaccinate contacts not immune - first dose within 7d of needle-stick, 14d sexual contact; check serology 4-8 weeks after vaccine
I - N/A
M -
E - sx, transmission, safe sex, safe injecting