differ by:
-mode of transmission
-liver damage they cause
-how they affect health
Most common cause of liver disease worldwide.
Mild attacks are asymptomatic.
May be acute or chronic.
Can occur at any age.
acute viral hepatitis:
- <6mths
-observed with all types
chronic viral hepatitis:
-viremia and hepatic inflammation >6mths following infection
-hep B,C and D
-may lead to cirrhosis and end stage liver disease
hepatitis A
only host virus - humans
no reported cases of
chronic hepatitis
major cause of acute hepatitis
most attacks are mild
mode of transmission:
faecal-oral route
risk factors
international travels
to endemic areas
sexual
contact
shell fish with the virus
IV drug users +
non-sterile needles
workers involved with
primate animals
food service handlers
patients with
clotting factors
disorders
healthcare workers
household contact with
infected person
diagnosis
antibodies to hepatitis A
virus in the serum
IgM - usually present about
3 weeks post exposure;
undetected within 6mths
IgG - present at the same time as IgM;
indicates protection and lifelong
immunity against infection
treatment
no drug treatment;
only supportive
Nota:
significant nausea, vomiting, diarrhoea and encephalopathy - hospitalisation required
prevention
good personal hygiene
& proper sanitary waste
disposal
immunoglobulin
Nota:
IM preparation
Provides passive immunity but not life long
effective for pre and post exposure prophylaxis against hepatitis A
hepatitis A vaccine
Nota:
-may be given alone or combined with typhoid vaccine
-provides effective active immunity
-adverse effects:
*injection site reactions
*headache
*fatigue
hepatitis B
blood borne infection
highest conc of virus -
blood & serous fluids
incubation
period
3-6mths
may be acute or chronic
mode of transmission
blood or body fluids through
peri-natal, sexual or IV drug use
blood
transfusions
from infected
donors
sexual intercourse
risk factors
about 1/3 reported cases
will have no identifiable
risk factors
men having sex
with other men
many heterosexual
partners
use of non-sterile needles
recipients of blood products
household contact with
hepatitis B with open wounds
healthcare providers
with contact with
contaminated needles
dialysis patients
diagnosis
surface antigen (HBsAg)
Nota:
-first to be detected in blood
-presence of recent infection
-chronic infection if present for >6mths
envelope antigen (HBeAg)
Nota:
-virus replication
-active acute infection if HBV DNA is also present