Hepatitis E virus (HEV) is one of the causes of viral hepatitis and is found worldwide. Although many infected individuals can recover without serious complications, certain groups, including pregnant women, people with weakened immune systems, and individuals with existing liver disease, may have a higher risk of developing severe illness.

One of the important concerns regarding hepatitis E infection is that the virus can spread through contaminated food and water, especially in areas with poor sanitation. Therefore, awareness of early symptoms and proper prevention methods play an important role in reducing the risk of infection.

What Is Hepatitis E Virus (HEV)?

Hepatitis E is caused by infection with Hepatitis E virus (HEV), a virus that primarily targets liver cells. Once the virus enters the body, it triggers inflammation in the liver, which can temporarily affect normal liver function.

Most HEV infections cause acute hepatitis E, meaning the infection occurs over a short period and can usually be cleared naturally by the immune system in people with normal immunity.

However, in some cases, especially among people with weakened immune systems, HEV infection may become chronic and lead to long-term liver damage.

How Is Hepatitis E Transmitted?

The most common way hepatitis E spreads is through consuming food or drinking water contaminated with the virus.

The virus enters the body through the digestive system. Common causes of transmission include:

• Drinking unsafe water contaminated with HEV
• Eating undercooked food, especially certain types of meat
• Consuming food prepared under poor hygiene conditions

In some regions, HEV can also spread from animals to humans, as certain animals may serve as reservoirs for the virus.

Symptoms of Hepatitis E

Some people infected with HEV may not experience symptoms or may only have mild symptoms, making it difficult to recognize the infection.

When symptoms occur, they may include:

• Fatigue and weakness
• Loss of appetite
• Nausea or vomiting
• Pain in the upper right side of the abdomen
• Fever
• Dark-colored urine
• Pale-colored stool
• Yellowing of the skin and eyes (jaundice)

These symptoms occur because liver inflammation affects the liver’s ability to function normally.

How Does Hepatitis E Develop?

After HEV enters the body, the virus replicates in liver cells and activates the immune response, causing inflammation of the liver.

Generally, hepatitis E can be divided into two main forms:

Acute Hepatitis E Infection
This is the most common form of the disease. Most patients recover within several weeks to months, and liver function usually returns to normal.

Chronic Hepatitis E Infection
This form is less common but may occur in people with weakened immune systems, such as organ transplant recipients receiving immunosuppressive medications or individuals with immune system disorders.
Chronic infection may cause ongoing liver inflammation and increase the risk of liver fibrosis.

People at Higher Risk of Severe Hepatitis E

Although most people with hepatitis E recover without serious problems, some groups have a higher risk of severe disease.

Pregnant Women
Pregnant women, particularly during the second and third trimesters, have a higher risk of complications from HEV infection compared with the general population.
In some cases, severe hepatitis may occur and affect both maternal and fetal health. Medical monitoring is important if symptoms suggest hepatitis infection.

People with Weakened Immune Systems
Individuals with reduced immune function, such as organ transplant recipients, people taking immunosuppressive medications, or those with certain immune disorders, may have difficulty clearing HEV from the body and may develop chronic infection.

People with Existing Liver Disease
Individuals with pre-existing liver conditions, such as cirrhosis or impaired liver function, may experience greater liver damage if they become infected with hepatitis E.

Complications of Hepatitis E

In healthy individuals, HEV infection usually does not cause long-term problems. However, complications may occur in some cases.

Severe Hepatitis
Some patients may develop severe liver inflammation, causing the liver to function improperly. Symptoms may include significant jaundice, extreme fatigue, or abnormal blood clotting.

Chronic Infection
Although uncommon, chronic infection may occur in people with weakened immune systems. Persistent infection can cause continuous liver inflammation and progressive liver damage.

Effects on Pregnancy
Pregnant women infected with HEV, especially during late pregnancy, may have an increased risk of complications affecting both the mother and baby.

Diagnosis of Hepatitis E

Doctors diagnose hepatitis E by evaluating symptoms, medical history, possible exposure risks, and laboratory tests.

Diagnostic tests may include:

• Blood tests to evaluate liver function, such as liver enzyme levels
• Testing for antibodies against HEV
• Detection of viral genetic material (HEV RNA), especially in people with weakened immune systems

Because symptoms of hepatitis E may resemble other types of hepatitis, additional testing is important to confirm the diagnosis.

Treatment of Hepatitis E

In people with normal immune function, hepatitis E usually resolves on its own. Treatment focuses on supportive care and reducing stress on the liver, including:

• Getting adequate rest
• Maintaining proper hydration
• Eating a balanced and nutritious diet
• Avoiding alcohol and substances that may harm the liver
• Taking medications as advised by healthcare professionals

For patients with chronic infection or weakened immune systems, doctors may consider specialized treatments, such as adjusting immunosuppressive medications or using antiviral therapy when appropriate.

Prevention of Hepatitis E Infection

Preventing HEV infection focuses on reducing exposure to the virus and maintaining good hygiene practices.

Eat Properly Cooked Food
Consume meat and seafood that are thoroughly cooked. Avoid raw or undercooked foods that may contain the virus.

Drink Safe Water
Choose clean and safe drinking water, especially when traveling to areas where sanitation risks are higher.

Practice Good Personal Hygiene
Washing hands with soap before eating, after using the restroom, and before preparing food is an important way to reduce the spread of infection.

Take Extra Precautions for High-Risk Groups
Pregnant women, people with weakened immune systems, and individuals with existing liver disease should take additional precautions to reduce infection risk.

Summary

Hepatitis E virus (HEV) is an infectious disease that affects the liver and can spread through contaminated food and water. Although most infected individuals recover naturally, certain groups, including pregnant women, people with weakened immune systems, and those with existing liver disease, may face a higher risk of severe complications.

Preventive measures, including eating properly cooked food, drinking safe water, and maintaining good hygiene, are essential for reducing the risk of infection. Recognizing abnormal symptoms and seeking medical evaluation when necessary can help ensure appropriate management and reduce the risk of long-term liver damage.

Prepared by: ภญ. ปุณยนุช อังคะนาวิน

References

1. World Health Organization. Hepatitis E
2. Centers for Disease Control and Prevention. Hepatitis E
3. Mayo Clinic. Hepatitis E