Causes of Hepatitis E

Hepatitis E is a liver disease caused by the Hepatitis E virus (HEV), which is transmitted primarily through the fecal-oral route. While it often results in a self-limiting illness, hepatitis E can become serious, especially in pregnant women and individuals with weakened immune systems. Understanding the causes and transmission pathways of this virus is crucial to preventing its spread and ensuring timely treatment.

Unlike other types of viral hepatitis, hepatitis E is most commonly transmitted through contaminated water and poor sanitation making it a serious public health concern in developing regions with limited access to clean drinking water and hygiene facilities. However, in recent years, rising cases in developed countries linked to undercooked meat and zoonotic transmission have drawn attention to the global nature of the disease.

What Is Hepatitis E?

Hepatitis E is an inflammation of the liver caused by infection with the Hepatitis E virus. HEV is one of the five main types of hepatitis viruses (A, B, C, D, and E) and is particularly prevalent in areas with poor sanitation and limited access to clean drinking water. The infection is usually acute and does not lead to chronic liver disease, although in rare cases, it can become severe or even fatal.

How Does Hepatitis E Spread?

Hepatitis E is predominantly spread via the fecal-oral route, meaning the virus enters the body when a person consumes food or water contaminated with feces from an infected person or animal. In regions where hygiene and sanitation are compromised, this form of transmission is very common. In more developed countries, the disease can also spread through undercooked meat and contaminated blood transfusions, although this is less frequent.

Major Causes of Hepatitis E

• Contaminated Drinking Water

The most common cause of hepatitis E, especially in developing nations, is the consumption of water contaminated with fecal matter containing the virus. Flooding, poor sewage disposal systems, and inadequate access to safe water sources all contribute significantly to the spread of HEV. Outbreaks often occur during rainy seasons or after natural disasters, when sanitation infrastructure is overwhelmed or damaged.

• Poor Sanitation and Hygiene

Inadequate sanitation and improper handwashing practices can lead to the rapid spread of hepatitis E in densely populated areas. When hands are not washed properly after using the toilet or before preparing food, there is a high risk of fecal contamination, which may then lead to HEV transmission. Shared household items and surfaces can also become vehicles for spreading the virus if hygiene is neglected.

• Consumption of Undercooked or Raw Meat

In some parts of the world, hepatitis E can be transmitted through the consumption of undercooked or raw meat from infected animals, particularly pork, wild boar, and deer. HEV genotype 3 and 4 are zoonotic and can infect both animals and humans. Improperly cooked meat, liver, or other organs from these animals can harbor the virus and cause infection when ingested.

• Animal-to-Human Transmission (Zoonotic Transmission)

Zoonotic transmission is increasingly recognized as a cause of hepatitis E in industrialized countries. Domesticated pigs, wild boars, and deer are known reservoirs for HEV. People who work in close contact with animals, such as farmers, butchers, and veterinarians, may be at increased risk. Direct contact with infected animals or their bodily fluids can lead to the spread of the virus.

• Blood Transfusion and Organ Transplantation

Though less common, hepatitis E can also be transmitted through infected blood products or organ transplants. This typically occurs when donors carry the virus asymptomatically, and their blood is not adequately screened for HEV. In recent years, some countries have introduced routine HEV screening for blood donations to prevent such transmissions, especially to immunocompromised patients.

• Mother-to-Child Transmission

Vertical transmission of hepatitis E from a pregnant woman to her unborn child can occur, particularly in the third trimester. While this is a rare cause, it is one of the most dangerous scenarios. Hepatitis E during pregnancy is associated with a higher risk of complications such as fulminant hepatitis, miscarriage, stillbirth, and maternal mortality. Therefore, preventing infection in pregnant women is a critical public health goal.

• Traveling to Endemic Areas

International travelers visiting regions with poor sanitation and high rates of hepatitis E are at risk of contracting the virus, especially if they consume unfiltered water, raw vegetables, or street food. Countries in South Asia, Southeast Asia, the Middle East, and Africa frequently report outbreaks. Travel-related HEV infections are preventable with proper precautions, such as drinking bottled or boiled water and avoiding uncooked foods.

High-Risk Populations

While hepatitis E can affect anyone, certain groups are more vulnerable to severe illness and complications :-

1. Pregnant women :- especially during the third trimester.

2. People with pre-existing liver diseases :- such as hepatitis B or cirrhosis.

3. Immunocompromised individuals :- including organ transplant recipients and patients undergoing chemotherapy.

4. Elderly individuals :- who may have weaker immune responses.

Preventing Hepatitis E: Key Recommendations

Preventing hepatitis E largely involves improving sanitation and personal hygiene. Here are a few simple but effective preventive strategies :-

1. Drink only clean, filtered, or boiled water.

2. Practice thorough handwashing with soap and clean water, especially before meals and after using the toilet.

3. Avoid eating raw or undercooked meat, especially pork and game meat.

4. Be cautious while traveling to endemic areas stick to bottled beverages and cooked foods.

5. Ensure proper screening of blood products and organ donors in healthcare settings.

Currently, a vaccine for hepatitis E (Hecolin) is available in China but is not yet widely distributed globally. Research is ongoing to expand its availability and usage worldwide.

Conclusion

Understanding the causes of hepatitis E is essential in preventing its spread and protecting vulnerable individuals from severe illness. Most hepatitis E infections result from contaminated water and poor hygiene, which are preventable with improved sanitation practices. However, growing evidence also highlights zoonotic transmission and foodborne routes, especially in developed countries.