Hepatitis A Flashcards
Hep A is caused by what virus
Picornavirus
which is stable in environment for months but humans are the only natural host
Mode of action of Hep A virus
fecal-oral transmission
incubation 28 days (range 15 - 50)
viral shedding from 10 days following exposure to 3 wks after onset of symptoms
Hep A symptoms
abrupt fever, anorexia, dark urine, jaundice
Hep A symptoms last
up to 2 mos with relapse up to 6 mos
Who should get routine Hep A vacc
all children 1 to 2 yrs
catchup by preschool if poss
catchup by 18 especially if risk factors
adults if risk factors present
Hep A Vaccines
Havrix (GSK) and Vaqta (Merck)
brands interchangeable
give 2 dose 6 mos apart
Twinrix (GSK) Hep A (ped dose) + Hep B (adult dose) - 3 dose series
Dosing of Hep A
- 5 ml IM if 18 or younger
1. 0 ml IM if 19 and older
Hep B
Hepadnaviridae
also stable in environment for 7 days but humans only known host
Hep B mode of action
blood-borne pathogen
incubation is 45-160 days
Preicteric
3-10 days - anorexia assoc symptoms
Hep B signs and symptoms
more common in adults than children
Preicteric
Icteric
Convalescence
jaundice, yellow skin and eyes, dark urine
target groups for Hep B Vacc
all infants
all adolescents who have not been prev vaccinated
all high-risk adults
recommended Hep B vacc schedule
infants:
birth
1-2 mo
6 mo (no earlier than 24 weeks)
adolescents and adults
0, 1, 6 mos
Hep B dosing
0.5 ml, 1 ml, and 2ml IM
immune due to Hep B vacc when
anti-HBs pos with >10
What if a health care provider’s Hep B titer is zero
give 1 dose
repeat titer 1 mo later
if high, no more doses needed
if low or none, complete series
Hep A target groups / risk factors for vaccination
all infants at least 1 year old
CLD
men who have sex with men
illicit drug users etc
Hep B risk factors
Heterosexual encounters
injection drug use
etc.
Hep B complications
10% liver cancer, death
