Countries / areas with moderate to high risk of Hepatitis B infection (Source from WHO)

Hepatitis B

• Hepatitis B is another type of viral hepatitis that leads to acute hepatitis. It can be followed by chronic liver damage, including cirrhosis and liver cancer.
• It has an incubation period of 6 weeks to 6 months.
• About 5-10% of infected adults and 70-90% of infected infants are unable to clear the virus, therefore becoming chronic carriers and serving as a source of infection to others.

Epidemiology

HBV infection occurs throughout the world. It is estimated that more than 2 billion people have been infected, of which more than 350 million have chronic life-long hepatitis B infection. In Southeast Asia including Hong Kong, the overall prevalence of chronic hepatitis B infection is high (>8%).

Transmission of Hepatitis B

The hepatitis B virus is found in the body fluids of an infected patient or a carrier, mainly in the form of blood, amniotic fluid, semen and vaginal secretions.

Routes of transmission:

1. Perinatal transmission
   A carrier mother usually transmits hepatitis B virus to an infant perinatally.
   
   The chance of perinatal transmission is more than 90%. In areas of high endemicity like Hong Kong and China, this is a major route of transmission.

2. Blood contact

• Accidental contact with an infected person's blood or body fluids through skin cuts, abrasion, or mucosal membranes of the eyes and mouths.
• Sharing injection instruments for drug injection.
• Using contaminated instruments for ear-piercing, tattooing or acupuncture.
• Sharing personal items such as razors, shavers or nail trimmer which may have been contaminated with blood.
  
  
3. Sexual contact
   Unprotected sexual contact with a carrier

Prevention of Hepatitis B

Hepatitis B is one of the diseases that can be transmitted by blood and body fluids, therefore the precautions are the same as those against other blood-borne infections.

1. Handle an open wound carefully; make sure it is properly bandaged.

2. Wear gloves when you expect to be in contact with blood. Blood stains can be cleaned with 1 parts of bleach diluted with 4 parts of water.

3. Do NOT share razors and toothbrushes or needles with other people.

4. Be careful if you decide to undergo procedures like tattooing and mole removal. Make sure clean, disposable instruments are used.

5. Limit the number of your sexual partners. Practice safer sex and use the condom properly. If your sexual partner is known to be a carrier, receive the hepatitis B vaccine as soon as possible.

Prevention by Hepatitis B Vaccination

• The most effective method is through hepatitis B vaccination.
• The complete course of vaccination takes a total of three injections. The second injection is given 1 month after the first, and the third injection 5 months after the second.
• About 90 to 95% of people will gain life-long immunity to hepatitis B after a full course of vaccination.
• Preferably have blood tests before vaccinated. Only people who have never been exposed to hepatitis B should have vaccination.

Who should receive vaccination against hepatitis B

Vaccination against hepatitis B may be considered in the following groups of people:

• Newborns
• Household and sexual contacts of carriers
• Intravenous drug users
• People who receive blood or blood products on a regular basis
• People on dialysis
• Health care workers who might be in contact with blood or other body fluids.