Hepatitis E Virus
Hepatitis E virus infection is caused by the Hepatitis E virus (HEV), which leads to inflammation of the liver. It results in symptoms similar to other viral hepatitis infections, such as jaundice, yellowing of the eyes, fatigue, or pain in the upper right abdomen. Infection is commonly acquired through consuming contaminated food or water. It is a disease found in many countries, including Thailand.
Most patients recover on their own, but in some cases, especially pregnant women and those with underlying liver diseases, the symptoms can be severe enough to cause liver failure. Therefore, symptoms should be monitored and appropriate medical evaluation sought.
This disease differs from Hepatitis A, B, and C viruses in that there is no widely used vaccine for prevention and no chronic infection in the general population (except in some immunocompromised individuals).
How many strains of HEV are there?
HEV has several genotypes found in humans and animals, each associated with different transmission patterns.
- Genotype 1 and 2 are found only in humans and transmitted through contaminated water, often causing outbreaks in developing countries.
- Genotype 3 and 4 are found in both humans and animals such as wild boars and deer → causing disease in people who consume undercooked meat.
In Thailand, Genotype 3 and 4 are most common; therefore, consuming undercooked or raw food, especially raw or semi-cooked pork liver, is a significant risk factor.
Causes and transmission routes
Hepatitis E virus is transmitted via the fecal–oral route through the gastrointestinal tract. The main transmission routes are as follows:
- Consumption of contaminated food or water is the most common cause, such as drinking water, ice from unclean sources, vegetables and fruits washed with dirty water, undercooked pork/wild boar/deer meat, and contaminated cooked or raw food.
- Contact with contaminated secretions or surfaces such as patient feces or food preparation without handwashing.
- Zoonotic transmission is mainly from pork, especially in Asian countries.
- Mother-to-child transmission is rare but can cause severe symptoms in both mother and infant if it occurs.
Symptoms of Hepatitis E virus
After infection, the incubation period is approximately 2–8 weeks. Symptoms may start gradually and can be divided into 3 stages:
- Pre-icteric phase (similar to general fever) Usually presents with low-grade fever, severe fatigue, muscle aches, nausea, vomiting, loss of appetite, abdominal pain and bloating.
- Icteric phase (clear hepatitis) Jaundice, yellowing of the eyes, dark urine resembling soy sauce, pale stools, pain or tightness in the right rib area, itching (in some cases).
- Recovery phase Symptoms gradually improve, liver enzyme levels (AST/ALT) decrease, and most recover within 4–6 weeks.
Symptoms that require urgent medical attention
- Increasing jaundice
- Drowsiness, fatigue to the point of being unable to work
- Loss of appetite
- Persistent vomiting
- Easy bleeding (a sign of liver failure)
Who are the high-risk groups that need special caution?
- Pregnant women (the most dangerous) are at risk of acute liver failure (Acute liver failure), preterm birth, miscarriage, or infant death. The mortality rate is much higher than in the general female population.
- Patients with chronic liver disease such as Hepatitis B/C, cirrhosis → have a higher risk of severe disease.
- Immunocompromised individuals such as organ transplant patients, those on immunosuppressive drugs, and HIV patients.
- People who work in contact with animals / pork butchers such as slaughterhouse workers, pig farmers, and pork sellers.
Diagnosis of Hepatitis E virus infection
Doctors will assess symptoms, perform physical examination, and conduct blood tests as follows:
- Liver enzyme tests (LFT) with elevated ALT/AST levels indicate liver inflammation.
- Anti-HEV IgM antibody test confirms acute infection.
- Direct virus detection (HEV RNA – PCR) is the most accurate and used in complex cases such as pregnant women and immunocompromised patients.
- Liver function tests (Bilirubin / INR) help assess disease severity, such as liver failure.
Treatment of Hepatitis E virus infection
Hepatitis E (Hepatitis E) is a liver disease transmitted through contaminated food and water, commonly found in developing countries. Most patients recover within a few weeks, but some groups may develop severe complications. Therefore, understanding proper care is essential. Treatment focuses on supportive care, including:
- Adequate rest
- Avoiding alcohol consumption
- Avoiding hepatotoxic drugs such as overdose of paracetamol, unknown herbal medicines
- Drinking plenty of fluids to prevent dehydration
- Eating easily digestible, low-fat foods
Possible complications
Although most cases are not severe, some may develop dangerous complications such as
- Acute liver failure is common in pregnant women and patients with chronic liver disease.
- Abnormal bleeding occurs due to the liver’s inability to produce blood clotting proteins.
- Complications in infants if the mother is infected during the third trimester, there is a risk of preterm birth and infant death.
- Chronic infection occurs in immunosuppressed patients, such as organ transplant recipients.
If you have symptoms similar to Hepatitis E virus infection such as severe fatigue, dark urine, pale stools, right rib pain, loss of appetite, or the onset of jaundice and yellowing of the eyes, you should seek immediate medical evaluation to diagnose the cause correctly and prevent possible complications.
At Phyathai 2 Hospital, we have a specialized team of gastroenterology and hepatology doctors, along with a standard laboratory capable of accurately testing liver enzymes and viral infections. We also provide a convenient, fast, and safe patient care system to ensure you receive appropriate diagnosis and treatment at the most critical time.
Dr. Chote Luangchosiri
Director of the Center of Excellence in Gastrointestinal and Liver Endoscopy
Phyathai 2 Hospital
