a.. Pediatric Database (PEDBASE)
b.. Discipline: GI
c.. Last Updated: 4/04/94
HEPATITIS A
DEFINITION:
An infectious disease of the liver caused by the hepatitis A virus (HAV) resulting in
an acute hepatitis lasting several weeks to months.
EPIDEMIOLOGY:
a.. incidence: ?
b.. age of onset:
a.. any
b.. highest incidence in those less than 15 years of age with prevalence
increasing gradually in adults
c.. risk factors:
a.. endemic (worldwide but endemic in Mediterranean Countries, Africa, South and
Central America, Orient; lower socioeconomic groups)
b.. epidemic (military groups, water-, milk-, or food-borne epidemics)
c.. independent of sex (M=F) and race
PATHOGENESIS:
1. Etiology
1. Hepatitis A Virus
a.. a single-stranded RNA picornavirus 27 nm in diameter
b.. a nonenveloped virus with a nucleocapsid containing the RNA
c.. routes of infection:
a.. usually fecal-oral
b.. can be food (shellfish)-, milk-, or water-borne
c.. rarely parenteral (as viremia is transient and a carrier state does not
exist)
2. Hepatitis A
a.. also called infectious hepatitis, epidemic jaundice, acute catarrhal
jaundice
b.. fulminant form was called acute yellow atrophy of the liver
c.. secondary attack rate in household contacts is 10-20%
2. Pathogenesis
a.. infection -> 15-40 day incubation period -> virus detected in the cytoplasm of
hepatocytes shortly before acute onset of hepatitis -> hepatocellular damage (elevated
ALT) by immunologic factors -> decreased viral expression
b.. fecal shedding of HAV begins in the latter part of the incubation period and
persists for 1 week after the onset of jaundice (i.e., HAV infection is spread during
the preicteric phase but not after the first week of jaundice)
CLINICAL FEATURES:
1. Prodrome
a.. arthritis and rash are not present
2. Hepatitis
a.. acute onset with duration of illness ranging from several weeks to months
b.. while the preicteric phase can last up to 5 days, the icteric phase lasts from
days to months with a mean of 8-11 days in children
c.. generally Hepatitis A is a mild or inapparent infection in infants and young
children
1. Preicteric Phase
a.. 1. Fever
a.. may be absent in children but last up to 5 days in adolescents
b.. ranges from 37.8-40 C
b.. 2. Accompanying Signs/Symptoms
a.. abdominal pain
b.. anorexia
c.. headache
d.. hepatomegaly (tender)
e.. lethargy
f.. lymphadenopathy
g.. nausea/vomiting
h.. splenomegaly
2. Icteric Phase
a.. 1. Jaundice
a.. transition to the icteric phase is marked by the disappearance of
preicteric signs/symptoms in young children but the exacerbation of these
signs/symptoms in older children and adolescents
b.. accompanied by dark urine (biliuria) +/- clay-coloured stools
c.. Hepatitis A infection may be anicteric in infants and children less than
3 years of age
INVESTIGATIONS:
1. Serum
a.. 1. Alanine Aminotransferase (ALT)
a.. striking rise in level after the incubation period and lasts 2-3 weeks
b.. 2. Bilirubin
a.. transient elevation associated with the peak in ALT levels lasting from one
day to longer than one month
c.. 3. Serology
a.. anti-HAV is detected at the onset of signs/symptoms and is initially
predominantly IgM but then later exclusively IgG (after 12 months)
d.. 4. Viremia
a.. no longer present after the onset of jaundice
MANAGEMENT:
1. Supportive
a.. symptomatic
2. Prognosis
a.. Hepatitis A is generally a benign disease and complete resolution of the
hepatitis usually occurs
b.. does not result in chronic hepatitis, liver disease, or a carrier state (thus
a very low risk for perinatal transmission)
c.. there is an increased morbidity and duration of jaundice with increasing age
d.. mortality from a fulminant hepatitis is very rare:
a.. 0.1-0.2% in the general population
b.. less than 1% in pregnant women
a.. source from: http://www.icondata.com/health/pedbase/files/HEPATITI.HTM
