Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus (HAV) that affects over 1.4 million people worldwide annually. It spreads primarily through fecal-oral transmission, often due to poor sanitation or hand washing. While children often experience mild or no symptoms, adults usually experience jaundice, fatigue, abdominal pain, and elevated liver enzymes for 2 weeks to several months. There is no chronic infection or carrier state. Treatment focuses on supportive care, while prevention emphasizes vaccination and improved hygiene.

1. In Brief
Hepatitis A
Hepatitis A. In: Pickering LK, ed. 2003
Red Book: Report of the Committee
on Infectious Diseases. 26th ed. Elk
Grove Village, Ill: American Academy
of Pediatrics; 2003:309–318
Hepatitis A Virus Infections in the
United States: Model-based
Estimates and Implications for
Childhood Immunization. Armstrong
GL, Bell BP. Pediatrics. 2002;109:
839–845
Viral Hepatitis. From Prevention to
Antivirals. Review. Jonas MM. Clin
Liver Dis. 2000;4:849–877
Hepatitis A. Kemmer NM, Miskovsky EP.
Infect Dis Clin North Am. 2000;14:
605–615
Hepatitis A virus (HAV) infection occurs
worldwide, affecting 1.4 million people
annually and accounting for 20% to
40% of viral hepatitis cases in the
United States. In young children, HAV
infection often is asymptomatic or
characterized by mild, nonspecific man-
ifestations; in adults, acute infection
usually results in a clinical presentation
lasting from 2 weeks to several months.
HAV is highly contagious and spreads
from person to person, frequently by
fecal contamination and oral ingestion.
The most common source of infection is
through contact with an infected per-
son or ingestion of contaminated wa-
ter, ice, or food. This occurs under
conditions of poor sanitation or poor
hand washing, travel to endemic areas
of the world, or ingestion of raw or
undercooked shellfish (oysters, clams,
and mussels) from contaminated wa-
ters. Other important sources of infec-
tion are exposure to other children in
child care centers (particularly in large
centers and in those that enroll children
still in diapers), food-borne or water-
borne outbreaks, male homosexual ac-
tivity, and intravenous drug use. Trans-
mission by blood transfusion or from an
infected mother to a newborn is rare.
However, in approximately 50% of in-
fections, the source remains undeter-
mined. Fecal-oral spread from asymp-
tomatic children likely accounts for
most of the cases whose source is
unknown. The incubation period is
about 4 weeks, with a range of 15 to
50 days. The highest titers of HAV in
stool occur during the 1 to 2 weeks
before the onset of illness, and the
highest period of communicability is
about 1 week before through 1 week
after the onset of symptoms.
HAV infection is an acute, self-
limited disease that does not lead to
chronic hepatitis. Clinical manifesta-
tions can vary from asymptomatic to
fulminant hepatitis and to death (rare
and seen mostly in patients who have
underlying liver disease). It begins with
prodromal symptoms such as fever,
headache, malaise, fatigue, and non-
specific gastrointestinal symptoms
(anorexia, nausea, vomiting, diarrhea)
that may last from several days to a
week. This is followed by jaundice, dark
urine, acholic (pale or clay-colored)
stools, right upper quadrant pain, and
pruritus. The prodromal symptoms usu-
ally diminish when the jaundice appears.
Laboratory findings in symptomatic
patients include elevations of serum
aminotransferases (usually 1,000 IU/
dL), total and direct bilirubin, and alka-
line phosphatase. Serum bilirubin levels
above 10 mg/dL (171 mcmol/L) are
common. These are accompanied by
elevations in acute-phase reactants
such as erythrocyte sedimentation rates
and immunoglobulins. An acute HAV
infection is diagnosed by detection of
immunoglobulin (Ig)M anti-HAV anti-
bodies in a patient’s serum. This peaks
during the acute or early convalescent
phase of illness and remains positive for
4 to 6 months. IgG anti-HAV antibodies
appear early in the convalescent phase
of the disease and remain detectable
for decades.
Treatment of hepatitis A infection is
supportive. General control measures
for prevention of infection are im-
proved sanitation and personal hygiene.
Hepatitis A vaccine is available as an
inactivated vaccine and is recom-
mended for children 2 years and older
in high-risk areas, administered in two
doses 6 to 18 months apart. Immune
globulin against HAV is available and
given via intramuscular injection for
pre-exposure and postexposure prophy-
laxis. Children and adults who have
acute HAV infection who work as food
handlers or in child care centers should
be excluded from such work for 1 week
after the onset of symptoms.
Samer S. El-Kamary, MD, MPH
Johns Hopkins University School of
Medicine
Baltimore, Md
Comment: Hepatitis A is one of the
most frequently reported vaccine-
preventable infections in the United
States. In 1998, more than 23,000 clin-
ical cases were reported to the Centers
for Disease Control and Prevention; the
highest rates were among children 5 to
14 years of age. Those who should be
immunized for hepatitis A are: children
living in United States communities
that have consistently high hepatitis
A rates, those who engage in foreign
travel (active or passive prophylaxis),
people who have chronic liver disease,
homosexual and bisexual men, users of
in brief
Pediatrics in Review Vol.26 No.2 February 2005 75
at Nyu Medical Center on June 6, 2015http://pedsinreview.aappublications.org/Downloaded from

2. illegal drugs, patients who have clot-
ting factor disorders, and people at risk
of occupational exposure. Areas that
have consistently high rates of hepatitis
A are defined as those states, counties,
or communities in which the average
annual reported incidence during 1987
to 1997 was equal to or greater than
twice the national average (20 cases
per 100,000). Two hepatitis A vaccines
are approved for those 2 years of age
and older and are given in two doses at
least 6 months apart. Combination im-
munizations that include hepatitis A for
children are being developed.
Tina L. Cheng, MD, MPH
Associate Editor
ATTENTION ARTISTS AGES 5 TO 16 YEARS
ART CONTEST FOR COVERS OF THE
YEAR 2006 AND 2007 ISSUES OF
PEDIATRICS IN REVIEW
INSTRUCTIONS TO ARTISTS:
Your drawing should be no smaller than 8.5Љ ϫ 11Љ and no larger than 18Љ ϫ 24Љ. Remember that your drawing
will be reduced to 5.5Љ ϫ 6Љ on the cover of the journal, so:
Make your drawing COLORFUL. Try to make your drawing fit the space (vertical, not horizontal). Draw
about . . .
Your favorite thing to do
Your dream of what you would like to happen someday
What you would like to be doing when you grow up
Entry Information (please fill in ALL information):
Name: Age:
Address:
City/State/Zip:
Pediatrician’s Name: Telephone #
Artwork should be submitted WITH THIS FORM TO:
Sydney Sutherland
Editorial Assistant, PIR
c/o Dept. of Pediatrics, Box 777
University of Rochester Medical Center, Room 4-8104
601 Elmwood Avenue
Rochester, NY 14642
ALL ENTRIES MUST BE RECEIVED BY DECEMBER 30, 2005
CLINICIANS: Please post this notice in your office FOR YOUR PATIENTS!
in brief
76 Pediatrics in Review Vol.26 No.2 February 2005
at Nyu Medical Center on June 6, 2015http://pedsinreview.aappublications.org/Downloaded from

3. DOI: 10.1542/pir.26-2-75
2005;26;75Pediatrics in Review
Samer S. El-Kamary
Hepatitis A
Services
Updated Information &
http://pedsinreview.aappublications.org/content/26/2/75
including high resolution figures, can be found at:
References
http://pedsinreview.aappublications.org/content/26/2/75#BIBL
This article cites 3 articles, 1 of which you can access for free at:
Subspecialty Collections
ases_sub
http://pedsinreview.aappublications.org/cgi/collection/infectious_dise
Infectious Diseases
following collection(s):
This article, along with others on similar topics, appears in the
Permissions & Licensing
http://pedsinreview.aappublications.org/site/misc/Permissions.xhtml
in its entirety can be found online at:
Information about reproducing this article in parts (figures, tables) or
Reprints
http://pedsinreview.aappublications.org/site/misc/reprints.xhtml
Information about ordering reprints can be found online:
at Nyu Medical Center on June 6, 2015http://pedsinreview.aappublications.org/Downloaded from

4. DOI: 10.1542/pir.26-2-75
2005;26;75Pediatrics in Review
Samer S. El-Kamary
Hepatitis A
http://pedsinreview.aappublications.org/content/26/2/75
located on the World Wide Web at:
The online version of this article, along with updated information and services, is
Pediatrics. All rights reserved. Print ISSN: 0191-9601.
Boulevard, Elk Grove Village, Illinois, 60007. Copyright © 2005 by the American Academy of
published, and trademarked by the American Academy of Pediatrics, 141 Northwest Point
publication, it has been published continuously since 1979. Pediatrics in Review is owned,
Pediatrics in Review is the official journal of the American Academy of Pediatrics. A monthly
at Nyu Medical Center on June 6, 2015http://pedsinreview.aappublications.org/Downloaded from