Education Corner

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 hepatitis B 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 worldwide, of which more than 350 million have chronic liver infection. Hepatitis B is endemic in Southeast Asia. In Hong Kong, the overall prevalence of chronic hepatitis B infection is moderate.

Transmission of Hepatitis B

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

Routes of transmission:

1. Perinatal transmission
   A chronic hepatitis B 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 an infected person.

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. Disinfect items contaminated by blood or body fluid with household bleach. Use gloved hands to handle splashes of blood and body fluid and perform hand hygiene after cleansing.
   -For blood, cleanse the visible matter with disposable absorbent material soaked with 1 part of household bleach into 4 parts of water (1:4). After leaving for 10 minutes, rinse with water.
   -For blood-stained clothing, soaked with 1 part of household bleach into 49 parts of water (1:49) for 30 minutes then washed as casual.
   -For other body fluids, cleanse the visible matter with disposable absorbent material soaked with 1 part of household bleach into 49 parts of water (1:49). After leaving for 30 minutes, rinse with 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 chronic hepatitis B, 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 chronic hepatitis B
• 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.
  
  

Medical treatment of Chronic Hepatitis B (CHB)

• Your doctor may perform tests such as liver function tests, alpha-fetoprotein, blood level of virus, and ultrasonographic liver examination etc. These will guide clinical management, including the use of antiviral drugs.
• Antiviral drugs are able to suppress HBV replication and thereby reduce virus-induced liver damage. Examples of first-line antivirals include entecavir and tenofovir. Consult your doctor for the appropriateness of these drugs.
• For people with CHB who require immunosuppressive therapy, such as high dose steroid or chemotherapy, your doctor will decide whether treatment is needed to protect your liver.

Source: https://www.info.gov.hk/hepatitis/english/hep_b_set.htm