Chester County Medicine Winter 2019 - 8

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Hepatitis A:

A New Outbreak
BY RENÉE M. CASSIDY, MD, FAAP, FACP
@ReneeCassidyMD * rcassidy@chesco.org

ou are likely familiar with several prominent hepatitis A
outbreaks which made the news in years past: an outbreak
affiliated with green onions at a restaurant, or the ones
linked to pomegranate seeds or strawberries imported from abroad.
Transmission of hepatitis A by contaminated food or water remains
a risk, but in recent years we have seen an increase in hepatitis A
among people experiencing homelessness, men who have sex with
men, and people who use drugs. Since March 2017, the Centers
for Disease Control and Prevention (CDC) has assisted health
departments in several states with person-to-person outbreaks of
hepatitis A. Nearby states including Ohio, Kentucky, and West
Virginia have seen a dramatic increase in cases, with a majority
of cases in the vulnerable populations mentioned above. Ohio
reported 1,370 cases in the current outbreak (as of 1/7/19),
Kentucky reported 3,265 (as of 12/15/18) and West Virginia
reported 2,214 (as of 1/11/19). Given the similarity of these
states to Pennsylvania (especially with respect to opioid use), the
Commonwealth has issued a health alert for help in identifying
and preventing infections. While Pennsylvania has thus far
reported only 102 cases (as of 1/11/19), this is nearly double the
average annual number of cases from 2012-2016, and is expected
to rise.

Hepatitis A Basics
Hepatitis A is caused by the hepatitis A virus (HAV), a singlestranded RNA virus in the picornavirus family. Usually, HAV
causes a self-limited infection that provides lifelong immunity.
Rarely, fulminant liver failure may occur, but no chronic form
exists. Humans are the only known reservoir, and people are
affected around the world. The disease may be sporadic or
epidemic, with incidence declining since the development of a
vaccine in 1992. HAV is spread through the fecal-oral route, thus
good sanitation and hygiene practices aid in the prevention of

8 CHESTER COUNT Y Medicine | WINTER 2019

HAV. Worldwide, there are an estimated 1.4 million infections
per year. In the US, the vaccine was recommended by the
Advisory Committee on Immunization Practices (ACIP) for those
at increased risk in 1996, for children in high incidence states in
1999, and for all children in 2006. Thus, we have seen a dramatic
decline in incidence. Prior to the introduction of the vaccine
there were 12 cases per 100,000 population in the US (1995); by
2015, there were 0.4 cases/100,000. HAV is spread from person
to person through ingesting contaminated food or water, or close
personal contact with an infected person. Transmission through
sexual contact, in hospitals, through blood, and by any drug
use - not just injection - has been reported, but maternal-fetal
transmission has not been documented. Because the virus can be
shed in stool starting about 1 week before symptom onset, and
because the incubation period is 15 to 50 days, in many outbreaks
HAV has spread before the index case is even identified.

Clinical Considerations
Signs and symptoms depend largely on age. In children
younger than 6 years, up to 70% may have asymptomatic or
unrecognized infection. Symptoms may be nonspecific, such as
fever, malaise, poor appetite, abdominal pain, nausea, vomiting,
and diarrhea. In the small number of young children with jaundice
(yellowing of the skin and eyes due to bilirubin), laboratory
abnormalities like conjugated hyperbilirubinemia and elevated
transaminases generally begin around 1 week after symptom onset
and resolve in 2-3 months, and jaundice itself is usually present
for 2 weeks or less. In contrast, 70% of older children and adults
develop signs and symptoms, including fever, nausea, vomiting,
bilirubinuria (dark urine), acholic stools (pale stools), jaundice (40
to 70%), and liver enlargement (80%). Less commonly, adults
and older children may develop rashes, joint pain, hematologic
abnormalities, vasculitis, and other extrahepatic findings. The vast

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Chester County Medicine Winter 2019

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