Hepatitis A and E Acute Viral Infections

Hepatitis A and Hepatitis E are the most common causes of acute viral hepatitis. The viruses are both RNA (Ribonucleic Acid) viruses which specifically target liver cells leading to rapid damage.

Hepatitis A (Hep A) is very commonly found in the environment in developing countries with poor sanitation and hygiene. In these areas, the infection occurs in childhood which is usually very mild or asymptomatic and they develop long lasting immunity. Areas with low risk of infections are prone to epidemics related to contaminated food and water.

Risk factors for Hepatitis A infection

• Travelers from nonendemic areas to regions with high risk of viral transmission
• Health care employees
• Employees at day care centres and elementary schools
• Patients with chronic hepatitis from Hepatitis B or C viruses
• Patients with other forms of chronic liver disease
• Immunocompromised individuals (HIV, immunosuppressive treatment)

Hepatitis E (Hep E) is found most commonly in India, parts of Asia, Central America and Africa. Areas with economic turmoil such as warzones and refugee camps have witnessed epidemics primarily through contaminated water sources. Some strains of Hep E can be found in the environment in, circulating in animals like pigs and wild boars.

Transmission of Hep A and Hep E viruses

Both viruses are transmitted through the feco-oral route, through contaminated food and water. Upon entry into the body, the virus reaches the blood stream and reaches the liver to attack it. The incubation period, which is the time it takes from entry of the virus into the body till symptoms appear is roughly 2 – 8 weeks.

Hepatitis A can also be transmitted through close physical contact with an infected person, during sexual intercourse. IV drug users are also at increased risk as the virus can be transmitted through blood on shared needles.

Hepatitis E can be acquired through ingestion of undercooked meat from infected animals and through blood products. Mother to child transmission during pregnancy can also occur if the woman is acutely infected during pregnancy.

Symptoms of Hep A and Hep E Acute Viral Hepatitis 

Not all infected individuals develop symptoms of illness. Some are asymptomatic and many might experience only a mild illness. The following symptoms are typically encountered in most patients

• Fever
• Body aches and joint pains
• Diarrhea
• Nausea and Vomiting
• Loss of Appetite
• Jaundice with yellowing of skin and whites of the eye
• Dark coloured urine
• Abdominal Pain usually localised to the right upper region
• Enlarged and tender liver

Diagnosis of Hep A and Hep E Acute Viral Hepatitis

The clinical picture in the setting of an outbreak in the area suggests the diagnosis. The following tests are done to confirm the diagnosis and assess the severity of infection.

1. Antibody testing of the blood: The IgM antibody against Hep A and Hep E is elevated during an acute infection.
2. Testing blood and stool for viral antigen can be done through reverse transcriptase Polymerase Chain Reaction (RT-PCR)
3. Liver function tests: The ALT and AST liver enzymes are elevated to the range of thousands during an acute illness. Serum bilirubin is also raised.

Treatment of Hep A and Hep E Acute Viral Hepatitis

There is no specific drug or antiviral medication to treat Acute Viral Hepatitis due to Hep A and Hep E. The management is supportive

1. Medications for fever and nausea are given
2. Avoid Paracetamol or acetaminophen (Tylenol) as it has the potential to damage the liver further
3. Adequate intake of high calorie food as this is required for recovery from liver cell injury

Complications of Hep A and Hep E Acute Viral Hepatitis

Acute Fulminant Hepatitis: In some individuals, the disease course can deteriorate with development of severe liver cell failure. These patients have the risk of hepatic encephalopathy from accumulation of ammonia in the body and bleeding abnormalities due to decreased production of clotting factors. Patients with underlying chronic hepatitis from Hep B or Hep C viruses and chronic liver disease are at an increased risk.

0.1-0.2% of patients with Hep A may progress to fulminant hepatitis. 1-2% of Hep E patients may develop it. In pregnant women with Hep E however, the risk of acute fulminant hepatitis rises to 10-20% putting the lives of both the mother and growing baby at risk.

Prognosis of Hep A and Hep E Acute Viral Hepatitis

Both conditions resolve completely, but take a few weeks to months before complete recovery. HepA can occasionally relapse and the person experiences symptoms a second time which is followed by full recovery.

These viruses do not remain in the body and there is no risk of chronic illness or carrier state. HepA and HepE are not associated with cancer of the Liver.

Prevention 

The best way to prevent infection from either virus is through good sanitation and hygiene practices. Handwashing while preparing meals and handling food, adequate cooking of food and proper sewage disposal drastically reduces risk of infection.

Hepatitis A can be effectively prevented by a vaccine carrying the inactivated virus. Two doses 6 months apart are recommended which provide nearly 100% protection from infection. The vaccine is recommended in those at high risk of infection. In case of an outbreak, vaccination within 2 weeks of exposure can successfully prevent infection.

A vaccine for HepE has been developed for use in China but is not available in other parts of the world.

References:

1. Hepatitis A [Internet]. World Health Organization. [cited 2018 Jul 28]
2. Hepatitis A | NIDDK [Internet]. National Institute of Diabetes and Digestive and Kidney Diseases. [cited 2018 Jul 28]
3. Hepatitis E | NIDDK [Internet]. National Institute of Diabetes and Digestive and Kidney Diseases. [cited 2018 Jul 28]
4. Hepatitis E [Internet]. World Health Organization. [cited 2018 Jul 28]