Hep A & B Flashcards
Hep A Background
- Enveloped RNA virus
- Piornavirus
- Causes acute infection only
- Spread via fecal oral route
- Can survive outside the body for months
Which antibodies are elevated in acute vs prior Hep A
-IgM = acute infection
(5 to 10 days)
-IgG = prior infection
(4 to 6mo)
Seroconversion rates for vaccine
- 94% with first dose
- Booster is still recommended
- Most common vaccine preventable infection
Why are Hep A rates highest in rural areas
-Lack of access
How many shots are in the Hep A schedule?
- Havrix and VAQTA are both a 2 shot series (0 and 6-12mo)
- Twinrix (HAV/HAB) is a 3 shot series (0, 1, 6mo)
Hep B background
- DNA virus that becomes a part of human DNA (cccDNA)
- Transmitted via percutaneous or mucosal contact with infected blood/ fluids
- Can live outside of the body for about 7 days
Hep B surface antigen (HBsAg)
- Protein found on the surface of HBV
- Detectable (+) in acute and chronic infections
Hep B surface antibody (anti-HBs)
- Will be (+) following successful vaccination series
- Antibody = made by us
- Antigen = made by virus
Hep B core antibody (Anti-HBc)
- (+) result indicates prior or ongoing infection
- If positive Anti-HBc and positive HBsAg then there is an active infection
- IgM = active infection
- IgG = prior/ chronic infection
Hep B vaccination
-3 dose series (0, 1, 6mo) 30 to 50% with 1st dose 75% with 2nd dose 96% with 3rd dose -Most patients do NOT finish series
Heplisav B
- 2 doses (0 and 1mo)
- New adjuvant = more robust immune response
- Pts are more likely to finish series
Immunoglobulins in Hep B
- Passive protection
- Used to prevent perinatal transmission
- Give w/in 24hrs of birth from HBV positive mother
- Not routinely used in adults
When to treat Hep B
- HBV > 2000 IU/mL
- ALT levels > ULN
- Pts with cirrhosis (compensated or decompensated)
Preferred treatments for Hep B
1) Entecavir- inhibits HBV polymerase
2) Tenofovir
TDF- requires renal adjustment
-Safe in pts with cirrhosis
Why do we not use interferons anymore?
- Lots of side effects
- Risk of decompensation