infection - blood borne viruses (Hep B)

Question 1

how is Hep B transmitted? incubation?

Answer 1

blood / sex / vertical
incubation: 6 weeks - 6 months
chronic

Question 2

who is at risk of hep B in terms of transmission?

Answer 2

vertical: mother to child
IV drug users
sexual contact
long term close household contacts
healthcare workers (needlestick)

Question 3

what are the symptoms of acute hep B?

Answer 3

(hepatic) jaundice - liver
fatigue - chronic disease
abdo pain
anorexia / nausea / vomiting - GI
arthralgia (joint pain)

Question 4

how / when does Hep B present?

Answer 4

incubation: 6 weeks - 6 months
AST / ALT in 1000s
up to 50%: vague / no symptoms
clear infection within 6 months
becomes chronic in 6-10%
1% hepatic failure

Question 5

what are the Hep B serology?

Answer 5

HBsAg (surface antiGEN first)
HBeAg (followed by e-antiGEN - highly infectious)
HBcAb (core antibody IgM - 1st antibody)
HBeAb (e-antibody follows - disapperance of infectivity)
HBsAb (last antibody: surface antiBODY - clearance of virus / recovery)
HBcAb (core antibody IgG persists for life)
secesc

Question 6

what is the definition of chronic hep B infection?

Answer 6

persistence of HBsAg after 6 months (1st antigen)
25% chronic infection leads to CIRRHOSIS
5% develop HEPATOCELLULAR carcinoma

Question 7

what are the treatments for Hep B?

Answer 7

NO CURE
life-long anti-virals to suppress viral replication
not required for everyone (e.g. inactive carrier) - low virulence level / normal LFTs / mild fibrosis

Question 8

are there vaccinations for Hep B?

Answer 8

genetically engineered surface antigen (HBsAg)
3 doses + boosters if required
effective in most people
produces SURFACE ANTIBODY (HBsAb) response

Question 9

when is HBsAg, HBcAb & HBsAb present?

Answer 9

HBsAg: only during infection
HBsAb: post exposure
HBcAb: during acute/ past / chronic infection (any)