PEDBASE.org - The Pediatric Database - Detailed information of HEPATITIS A

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.

incidence: ?
age of onset:
- any
- highest incidence in those less than 15 years of age with prevalence increasing gradually in adults
risk factors:
- endemic (worldwide but endemic in Mediterranean Countries, Africa, South and Central America, Orient; lower socioeconomic groups)
- epidemic (military groups, water-, milk-, or food-borne epidemics)
- independent of sex (M=F) and race

a single-stranded RNA picornavirus 27 nm in diameter
a nonenveloped virus with a nucleocapsid containing the RNA
routes of infection:
- usually fecal-oral
- can be food (shellfish)-, milk-, or water-borne
- rarely parenteral (as viremia is transient and a carrier state does not exist)

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
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)

acute onset with duration of illness ranging from several weeks to months
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
generally Hepatitis A is a mild or inapparent infection in infants and young children

1. Fever

2. Accompanying Signs/Symptoms

1. Jaundice

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
accompanied by dark urine (biliuria) +/- clay-coloured stools
Hepatitis A infection may be anicteric in infants and children less than 3 years of age

1. Alanine Aminotransferase (ALT)

2. Bilirubin

transient elevation associated with the peak in ALT levels lasting from one day to longer than one month

3. Serology

anti-HAV is detected at the onset of signs/symptoms and is initially predominantly IgM but then later exclusively IgG (after 12 months)

4. Viremia

Hepatitis A is generally a benign disease and complete resolution of the hepatitis usually occurs
does not result in chronic hepatitis, liver disease, or a carrier state (thus a very low risk for perinatal transmission)
there is an increased morbidity and duration of jaundice with increasing age
mortality from a fulminant hepatitis is very rare:
- 0.1-0.2% in the general population
- less than 1% in pregnant women

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