What is hepatitis E?

Definition

Hepatitis E is a viral liver infection transmitted through the intestinal
tract. Hepatitis E, which is an acute, short-lived illness that can sometimes
cause liver failure, is more common in regions of the world that lack clean water
and environmentally safe sanitation.

Causes

Hepatitis E is primarily spread by fecal-oral transmission. It is commonly
found in countries where human waste contaminates the water sources. Large
outbreaks have occurred in Asia and South America that have poor sanitation. In
the United States and Canada, no outbreaks have been reported, but persons
traveling to an endemic region may return infected with the hepatitis E virus
(HEV).

Risk Factors

Risk factors for hepatitis E are factors that do not seem to be a direct cause
of the disease. Hepatitis E occurs in both epidemic and
sporadic-endemic forms usually associated with contaminated drinking water. Because this disease is primarily a
result of a lack of water filtration in underdeveloped countries, there are no specific risks
associated with it. Water filtration systems are prevalent in most developed
countries, such as the United States, Canada, and China, and in the countries of
Europe. Historically, the only major waterborne epidemics have occurred in Asia
and North and West Africa.

Symptoms

The symptoms of hepatitis E include flulike symptoms, fever, fatigue, nausea, vomiting, loss of appetite, abdominal pain, diarrhea, and jaundice.

Screening and Diagnosis

Cases of hepatitis E are not clinically evident from other types of acute
viral
hepatitis. Diagnoses are usually made by blood tests that
detect elevated levels of specific antibodies to hepatitis E in the body
or by reverse transcriptase polymerase chain reaction. However, these tests are
not yet widely available.

When waterborne hepatitis occurs in developing countries, especially if the
disease is more severe in pregnant women, hepatitis E should be suspected if
hepatitis
A has been excluded. If laboratory tests are not available,
epidemiologic evidence can help in establishing a diagnosis.

Treatment and Therapy

Hepatitis E is classified as a viral disease, so there is no effective
treatment of acute hepatitis. Consequently, antibiotics
are of no significance in the treatment of the viral
infection. Hepatitis E infections usually remain in the
intestinal tract, and hospitalization is generally not required. However, there
are reports of HEV damaging and destroying liver cells, so much so that the liver
cannot function. This is called fulminant liver failure, a condition that can lead
to death. Pregnant women are at a higher risk of dying from fulminant liver
failure. This increased risk is not constant with any other type of viral
hepatitis.

The majority of persons who recover from acute infection do not continue to
carry HEV and, thus, cannot pass the infection to others. No available therapy can
alter the course of acute infection. Also, there are no vaccines for hepatitis E
that have been approved by the U.S. Food and Drug Administration.

Prevention and Outcomes

Prevention is the most effective approach against hepatitis E. The most effective way to prevent hepatitis E is to provide and consume safe drinking water and to take precautions to use sterilized water and beverages when traveling to an endemic region.

Bibliography

Feldman, Mark, Lawrence S. Friedman, and Lawrence J. Brandt, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. New ed. 2 vols. Philadelphia: Saunders/Elsevier, 2010.

Kamar, N., et al. “Hepatitis E Virus and Chronic Hepatitis in Organ-Transplant Recipients.” New England Journal of Medicine 358 (2008): 811-817.

Shrestha, M. P., et al. “Safety and Efficacy of a Recombinant Hepatitis E Vaccine.” New England Journal of Medicine 356 (2007): 895-903.