What is Hepatitis E
Hepatitis E virus (HEV) is an RNA virus with fecal-oral transmission. It is the only member of the hepevirus genus of the family Hepeviridae. The virus has at least 4 different types: genotypes 1, 2, 3 and 4. Genotypes 1 and 2 have been found only in humans. Genotypes 3 and 4 circulate in several animals (including pigs, wild boars, and deer) without causing any disease, and occasionally infect humans.
The virus is shed in the stools of infected persons, and enters the human body through the intestine. It is transmitted mainly through contaminated drinking water. Usually the infection is self-limiting and resolves within 2–6 weeks. Occasionally a serious disease, known as fulminant hepatitis (acute liver failure) develops, and a proportion of people with this disease can die.
According to the World Health Organization (WHO), 20 million cases of hepatitis E infection occur every year, and 44,000 of these cases resulted in death in 2015. It is more common in developing countries. It usually resolves itself, but may develop into acute liver failure.
What are the symptoms
If a person develops symptoms of hepatitis E, they show up within several weeks of exposure. They include:
What causes hepatitis E?
Most cases of hepatitis E are caused by drinking water contaminated by fecal matter. Living in or traveling to countries with poor sanitation can increase your risk. This is especially true in overcrowded areas.
More rarely, It can be transmitted by eating products from infected animals. It can also be transmitted through blood transfusions. An infected pregnant woman can also transfer the virus to her fetus.
Most cases of infection clear up on their own after a few weeks. In other cases, the virus causes liver failure.
How is It diagnosed?
To diagnose hepatitis E, your doctor will do a blood test to look for antibodies to the virus. Diagnosis can be challenging because distinguishing between different forms of hepatitis is difficult.
How is hepatitis E treated?
For people who have severe acute illness and who are not pregnant, treatment with the medication ribavirin for 21 days has resulted in improved liver function in some small studies.
If hepatitis E is suspected and your immune system is not suppressed, you may not need medications. A doctor may advise you to rest, drink plenty of fluids, avoid alcohol, and practice good hygiene until the infection subsides.
Pregnant women, people with suppressed immune systems, or people with acute liver failure will likely be hospitalized and monitored.
The virus is transmitted mainly through the fecal-oral route due to fecal contamination of drinking water. This route accounts for a very large proportion of clinical cases with this disease. The risk factors for hepatitis E are related to poor sanitation, allowing virus excreted in the faeces of infected people to reach drinking water supplies.
Other routes of transmission have been identified, but appear to account for a much smaller number of clinical cases. These routes of transmission include:
- ingestion of undercooked meat or meat products derived from infected animals (e.g. pork liver);
- transfusion of infected blood products; and
- vertical transmission from a pregnant woman to her baby.
Where is hepatitis E most common?
It is most common in developing countries with inadequate water supply and poor environmental sanitation. Hepatitis E epidemics involving large numbers of people have been reported in Asia, the Middle East, Africa, and Central America. People living in crowded camps or temporary housing, including refugees and people who are internally displaced, are at particularly high risk.
What are the different genotypes of hepatitis E and where can they be found?
HEV is unique, in that it has a different clinical and epidemiologic profile depending on where the infection is acquired. This can be attributed largely to the viral genotypes circulating in different parts of the world.
Four genotypes of HEV cause illness in humans, each displaying different epidemiologic and clinical characteristics in developing and developed countries. Cases of hepatitis E typically present in one of two ways: either as large outbreaks and sporadic cases in areas where HEV is endemic (genotype 1 in Asia and Africa, genotype 2 in Mexico and west Africa, and genotype 4 in Taiwan and China) or as isolated cases in developed countries like the United States (genotype 3).
Recently, a new genotype (genotype 7) was identified in a liver-transplant recipient from UAE with chronic hepatitis E virus infection who frequently consumed camel meat and milk
What is the outlook for hepatitis E?
Hepatitis E generally clears up on its own with few complications. In rare cases, it can lead to acute liver failure, which can be fatal.
Mortality rates for the virus are low. Pregnant women are most at risk for fatal complications. People with suppressed immune systems are more at risk for developing a chronic version of hepatitis E.
How to prevent hepatitis E
To avoid contracting such infection, be cautious about drinking unsanitary water.
In developing countries, drink only purified or boiled water. Avoid uncooked or unpeeled foods. These include fruit, vegetables, and shellfish, which are usually rinsed in water.
It is also important to practice good hygiene and wash your hands often.