Hepatitis E
Hepatitis E is a viral liver infection primarily transmitted through the fecal-oral route, commonly occurring in regions with poor sanitation and contaminated water sources. It is characterized as an acute, often short-lived illness that may lead to liver failure in severe cases, particularly affecting pregnant women. The hepatitis E virus (HEV) has been linked to large outbreaks in Asia and South America, though it is rarely seen in developed countries like the United States and Canada. Symptoms of hepatitis E resemble those of other viral hepatitis infections, including fever, fatigue, nausea, and jaundice.
Currently, there is no specific treatment for hepatitis E, and antibiotics are ineffective against this viral infection. Diagnosis is typically confirmed through blood tests, but these may not be widely accessible. Prevention is crucial and involves ensuring safe drinking water and adopting careful eating and drinking practices, especially for travelers to endemic regions. While most individuals recover from the infection without long-term effects, the risk of severe outcomes underscores the importance of proper sanitation and public health measures.
Hepatitis E
Anatomy or system affected:Gastrointestinal system, intestines, liver
Also known as: Hepatitis E virus
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, which 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 countries in Europe. Historically, the only major waterborne epidemics have occurred in Asia and North and West Africa.
Symptoms
The symptoms of hepatitis E include flu-like 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 for 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. For travelers to developing areas of the globe, the Centers for Disease Control and Prevention recommends consuming only sealed and commercially-produced beverages, avoiding ice, drinking only pasteurized milk, and eating hot and fully cooked food.
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.
“Hepatitis E: Disease Directory and Travelers' Health.” CDC, 21 Sept. 2022, wwwnc.cdc.gov/travel/diseases/hepatitis-e. Accessed 28 Feb. 2023.
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.