<英文>甲肝知识动漫

What is hepatitis A?

Hepatitis A is a liver disease caused by the Hepatitis A Virus. It is common in many developing countries. Hong Kong is a region with intermediate prevalence of hepatitis A. This virus is spread through:

• Fecal-oral route -
  • eating contaminated food without proper cooking (especially shellfish like oysters, clams, cockles and mussels)
  • drinking contaminated water
• Close personal contact with infected person

Children who are infected with hepatitis A often have milder symptoms than infected adults do. Hepatitis A presenting symptoms can include:

• tiredness
• muscle pain
• headache
• nausea, vomiting, diarrhea, upper abdominal pain
• yellowing of eye and skin (jaundice) and tea-coloured urine

Hepatitis A would rarely cause liver failure or death. Persons recovered from the infection develop lifelong immunity against the infection.

Risk for Travellers

Most young people in Hong Kong, below the age of 30, have never been exposed to hepatitis A, and therefore are susceptible to the infection. In endemic areas, 30 to 100 cases of hepatitis A are reported per 100,000 persons each year. In general, the less hygienic the area is, the higher the chance of infection.

 

How can travellers prevent themselves from getting hepatitis A ?

Travellers can pay attention to their personal and food hygiene:

• Washing hands thoroughly with soap before eating food or after going to the toilet.
• Avoid drinking beverages or iced drinks of unknown purity.
• Ensure all food is thoroughly cooked, particularly seafood and shellfish.
• Avoid eating uncooked vegetables and sliced fruit.
• These simple measures can effectively prevent travellers from getting hepatitis A infection or other gastrointestinal diseases including food poisoning, dysentery and cholera.
• In addition, travellers can consider hepatitis A vaccine or immune globulin injection. If you frequently travel to endemic areas, hepatitis A vaccination is preferable to immune globulin injection.

Vaccine and Immune Globulin

Hepatitis A vaccine does not substitute personal and food hygiene. As adults who are over 30 years old may already developed immunity against hepatitis A, hepatitis A serostatus should be checked before vaccination so as to avoid unnecessary injections and costs. A complete course of vaccination requires 2 injections, given 6 months to 18 months apart. The body takes 4 weeks to develop antibody against hepatitis A after the first vaccine injection. Therefore, travellers should start the first shot of vaccine at least one month before their journey to provide the best protection.

Travellers may also consider getting a shot of immune globulin which gives immediate but temporary protection. It is effective if the injection is given before hepatitis A exposure or within fourteen days after the exposure. Injection of immune globulin confers temporary protection to as long as 3 months. A dose of immune globulin may be given alone or in addition to hepatitis A vaccine administered at a different site.

Hepatitis A vaccine is not licensed for children younger than one year of age. Children less than one year old can consider immune globulin injection.

What are the adverse effects of Vaccine?

Like any medicine, hepatitis A vaccine could possibly cause adverse reactions. These reactions are usually mild and often last for only one to two days. The most commonly seen undesirable effect is injection site soreness. Other reactions include headache, loss of appetite and tiredness. Severe allergic reaction that occurs within a few minutes to a few hours of the shot is very rare.

Who should not get hepatitis A vaccine?

• Anyone who has ever had a severe life-threatening allergic reaction to the previous dose of hepatitis A vaccine or allergy to any vaccine component should not get another dose.
• Anyone who is moderately or severely ill should postpone the shot.
• Tell your doctor if you are pregnant. The safety of hepatitis A vaccine for pregnant women has not been determined. But there is no evidence that it is harmful to either pregnant women or their unborn babies.

Where can I get the shot?

For arrangement of hepatitis A vaccination, please consult your family doctor.