hep b

Question 1

Negative x 3
HBsAg
Anti-HBc
Anti-HBs

Answer 1

non-immune, not infected (susceptible)

Question 2

HBsAg negative
Anti-HBc positive
Anti-HBs positive

Answer 2

immune due to natural infection

Question 3

HBsAg negative
Anti-HBc negative
Anti-HBs positive

Answer 3

immune due to hep b vaccination

Question 4

HBsAg positive
Anti-HBc positive
IgM anti-HBc positive
Anti-HBs negative

Answer 4

acutely infected

Question 5

HBsAg positive
Anti-HBc positive
IgM anti-HBc negative
Anti-HBs negative

Answer 5

chronically infected

Question 6

HBsAg negative
Anti-HBc positive
Anti-HBs negative

Answer 6

• serologic window (recovering from acute infection)
• distantly immune, test not sensitive enough to detect very low level of Anti-HBs in serum
• false positive anti-HBc
• undetectable HBsAg and person is actually chronically infected

Question 7

where is HBcAg found? where is HBsAg found?

Answer 7

• hepatocytes

- serum

Question 8

what does HBeAg represent?

Answer 8

active replication/high infectivity

• associated with cirrhosis
• associated with liver cancer

Question 9

vertical transmission rate (if no ppx)

Answer 9

• if HBsAg pos: 20%
• if HBsAg + HBeAg: 90%
• 1st trimester acute infection: 10%
• 3rd trimester acute infection: 90%

Question 10

modes of transmission?

Answer 10

• during delivery (85-95%)
• transplacental
• close maternal contact after delivery

Question 11

neonatal tx?

Answer 11

• Hep B vaccine
• HBIG
• Both given within 12 hrs of delivery, at different IM sites

Question 12

what is the first antibody to show with hep b infection

Answer 12

• Anti-HBc IgM

Question 13

what is then serologic window?

Answer 13

when HBsAg is cleared, but HBsAb not yet detectable

Question 14

what is treatment for Hep A

Answer 14

• vaccineadn HbIg within 2 weeks; okay in preg