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Hepatitis A Virus


What is the hepatitis A virus?

The hepatitis A virus caused by a virus in the Picornaviridae family. It can cause acute inflammation of the liver.
Symptoms range from mild to severe and usually last less than 2 months.

Symptoms include (not all may be present):

  • Fever
  • Fatigue
  • Loss of appetite
  • Nausea and vomiting
  • Abdominal pain or discomfort
  • Dark urine
  • Diarrhea
  • Jaundice

Children younger than 6 years old usually have no symptoms. Most teenagers and adults will experience the symptoms of acute hepatitis, especially in people with chronic liver disease from other causes. Once people have been infected with the hepatitis A virus, they are permanently immune.

The hepatitis A virus can be transmitted by:

Eating or drinking contaminated food prepared by someone with the virus or eating uncooked food.

Who is at risk of hepatitis A?

  • People living with hepatitis A patients
  • People living or travelling in regions where hepatitis A outbreaks occur
  • Children or caregivers at nurseries
  • People living in crowded conditions; refugees living in temporary camps
  • People with chronic hepatitis or cirrhosis caused by alcohol or hepatitis B and C viruses

How is it prevented?

  • The best way to prevent infection with the hepatitis A virus is to wash your hands after using the toilet or before preparing food. Wear gloves when coming into contact with anybody’s feces and wash your hands thoroughly afterwards.
  • Vaccination is the most effective method of preventing infection.

Hepatitis A Vaccination

  • Immunity usually develops 4 weeks after the initial dose and will last for about 20 years.
  • It should be considered for children older than 2 years who are at risk of hepatitis A.
  • 3 doses are recommended at 0, 6, and 12
  • The hepatitis A vaccine can be administered at the same time as other vaccines, such as vaccines for hepatitis B, tetanus, diphtheria and Japanese encephalitis. People who have never received the vaccine and plan to travel to regions where outbreaks occur should be vaccinated 4 weeks before traveling.

Should persons be tested for immunity before or after being vaccinated?

  • In people younger than 18 years old: Testing for immunity is not usually required.
  • In people older than 18 years old: Testing for immunity is usually required because there are a lot of Thai adults who have developed immunity from previous infections.

What is immune globulin? Immune globulin is a substitute vaccine offering short-term protection against hepatitis A, must be given within the first two weeks after or before exposure. It is used for people who have allergies to the hepatitis A vaccination.

Samitivej, We Care

For further information,
please contact: Liver and Digestive Center
Samitivej Srinakarin Hospital
Internal Medicine Clinic, 4th floor
Tel: 66 (0) 2378-9084-5
Call Center: 66 (0) 2378-9000


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