Hepatitis A

Hepatitis is a disease in which inflammation occurs in the cells of the liver and hepatocytes are destroyed. 90% of this symptom is caused by infection of the virus.In Japan, it is said that 1 to 2 people in 100 people are infected with hepatitis virus, and there are those who are infected by the virus but have not apparant symptoms. This virus is much more common that many people think.

Hepatitis A is a transient infection caused by hepatitis A virus. It is rare to chronicize compared to hepatitis B and C. According to the Infectious Diseases Act, it is classified into 4 classes.
Hepatitis A is found mostly in feces and often infected orally. The number of infected patients may be determined by the type of food intake and influenced heavily by the hygiene of their immediate environment.In Japan, the number of occurrences is drastically decreasing due to maintenance of sewers. The disease is rarely seen from people who are under the age of 50 years old. Although in Japan occurences may be considered rare., 1.4 million people around the world have been affected by the sickness throughout the world. Majority of which has been occuringin the dveloping countries.

Transmission of Hepatitis A virus

The main source of Hepatitus A is from the consumption of contaminated food. According to the announcement by the National Institute of Infectious Diseases, 75% of all infection is from contaminate food and 20 % of which is from the consumption of oysters.
There were epidemic outbreaks in the past, due to shellfish. Currently out breaks may still happen but the cause of identifiable infection is via sexual intercourse.

Countries recommended for vaccine

Hepatitus A is prevalent throughout the world, except for America, Canada, Northern Europe, Western Europe, Australia and New Zealand. Its spread is especially apparent in South, Southeast, East Asia region, sub-Saharan Africa region and Latin America region.


The incubation period of hepatitis A virus is 2 to 7 weeks. Following the incubation period symptoms like fever, dullness, anorexia, nausea and vomiting arise. Jaundic (when skin and sclera turns yellow) appears in the next several days following initial infection. The long incubation period of the disease may lead to you being infected multipile times on a single trip. In addition, symptoms are more likely to appear in adults than in children, and elderly people have greater severity and mortality.

How to prevent and cure

It is necessary to stay in the hospital and rest during periods of incubation. During hospitalization, blood tests are carried out on a regular basis, observing the presence of severity, fulminant symptoms, etc. and continue surveillance for the formation of antibodies in the body. general prevention methods such as thorough hand washing, and actively being careful for hygiene and vaccination cycles is important.

Antibody duration is different in Japan and Thailand, because there is a difference in the usage of vaccinations.

■Vaccines used in Japan

・Number of inoculations: 3 times in total

・Inoculation frequency: First time,2 to 4 weeks, 6 to 12 months later

・Antibody duration: 5 years after the 3rd injection.

・Frequently used vaccines: Aimmugen (Production: The Chemo-Sero-Therapeutic Research Institute / Selling Agency:Astellas Pharma Inc)

■Vaccines used in Thailand

・Number of inoculations: Once or twice

・Inoculation frequency: Select one of the following

 Single dose: Only once

 Double dose: First time, 6 to 12 months later

・Antibody duration:

 Single dose: Acquire immunity for at least 1 year with the establishment of 99%.

 Double dose: Acquire immunity for at least 20 years with the establishment of 97%.

・Frequently used vaccines: Havrix1440 (GlaxoSmithkline)

<<The inoculation schedule difference between Aimmugen and Havrix 1440>>

・Inoculation frequency and schedules are the same.


There virus is apparent in poor sanitary conditions which include unboiled water, ice, raw meat and raw vegetables. It is better to consume mineral water, boiled water and cooked food.
Water used to rinse fruit may be polluted so we recommend you peel or clean produce indivdually. Also food should be well cooked and beverage intake should only be from well managed and sanitized places.

About the combined vaccine

It is unapproved in Japan, but Twinrix is used in abroad. Twinrix is a vaccine produced by Glaxo Smith Kline and it is a combination vaccine of hepatitis A and hepatitis B.

■Details about Twinrix.

・Number of inoculations: 3 times in total

・Inoculation frequency: First time,4 weeks, 6 months later

・Antibody duration: 15 to 20 years