Hepatitis A

 

  • Hepatitis A is one type of viral hepatitis. It usually leads to acute hepatitis and jaundice.

  • It has an incubation period of 6 days to 6 weeks.

  • Most patients have a complete recovery. The liver may be severely affected in a few cases.

 

Persons recovered from the infection develop lifelong immunity against the infection. There is no chronic carrier state.

 

Transmission of Hepatitis A

 

Hepatitis A is transmitted faeco-orally - the virus is transmitted from an infected person's stool to the water or food eaten by another person.

 

The virus can survive in water for more than a year and also in food for a few days, therefore it can be transmitted by:

 

  • eating contaminated food (especially shellfish like oysters, clams, cockles and mussels) without proper cooking;

  • drinking contaminated water;

 

close personal contact with infected person.

 

Prevention of Hepatitis A

 

To be careful with your personal, food and environmental hygiene.

 

  • Personal hygiene - wash your hands with soap before preparing or eating food and also after going to the toilet.

  • Food hygiene - drink only boiled water. All food, especially bivalve shellfish such as oysters, clams, mussels, and scallops, etc., should be carefully cleaned and thoroughly cooked.

 

Environmental hygiene - treat contaminated water and sewage properly; store drinking water properly and keep all kitchen utensils clean.

 

 

Being vaccinated against hepatitis A helps to produce antibodies to the virus. 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. Hepatitis A vaccine is not licensed for children younger than one year of age.

 

 

 

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.

 

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.

 

  1. 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.

 

  1. 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.

 

 

 

Hepatitis C

 

Hepatitis C is a liver disease caused by the hepatitis C virus.The incubation period ranges from 2 weeks to 6 months4.Compared to other forms of viral hepatitis, hepatitis C often goes unnoticed and develops into chronic disease (80% cases), posing a severe threat to liver health.

 

Hepatitis C can be classified into 6 different genotypes, with genotypes 2 and 3 having a better prognosis over genotype .Over time, it may lead to complications including cirrhosis (scarring of liver), liver failure and liver cancer8. Early diagnosis and treatment helps to limit disease progression and its complications.

 

Transmission of Hepatitis C

 

Hepatitis C is a blood-borne disease, it is commonly transmitted through:

 

- Sharing needles

- Sharing personal accessories (e.g. toothbrushes, razors)

- Exposure to inadequately sterilized medical equipment

- Contact with infected blood

- Tattooing and body piercing procedures (e.g. nose piercing)

- Unprotected sex

 

Nowadays, transfusion-related infections are extremely rare due to universal blood donor testing. In addition, hepatitis C cannot be transmitted through breast milk, casual contact (e.g. hugging and kissing) or sharing food and drinks, therefore, disease carriers can carry out their work and activities as normal.

 

Prevention

 

Currently, there is no vaccination against hepatitis C, but the risk can be reduced by the following methods:

 

- Avoid sharing personal accessories (e.g. toothbrushes, razors)

- Avoid high risk activities (e.g. tattooing, body piercing)

- Good personal hygiene (e.g. hand washing)

- Safe handling and disposal of sharps, blood and waste

- Use a condom while having sex

- Use sterile syringes for injections

 

If you are infected with hepatitis C, please seek advice from healthcare professionals.Besides early antiviral treatment, you should also be vaccinated against hepatitis A and B for further protection.

 

Symptoms

 

The incubation period of hepatitis C ranges from 2 weeks to 6 months. During acute infection, most patients (80%) actually feel quite healthy while some may experience rashes or joint pains.In cases of liver damage, the following symptoms may appear:

 

- Fever

- Fatigue

- Loss of appetite

- Nausea and vomiting

- Dark urine

- Grey-colored stool

- Abdominal and joint pain

- Jaundice (yellowing of skin and eyes)

 

If you are yourself to be infected, please consult your doctor immediately!

 

 

 

Hepatitis D

 

Hepatitis D is a unique virus. It needs hepatitis B virus to survive and replicate. For this reason, Hepatitis D is limited to people who are already carriers of hepatitis B.

 

If you are vaccinated against hepatitis B, you are automatically protected from hepatitis D as well.

 

 

 

Hepatitis E

 

  • Hepatitis E is one form of viral hepatitis caused by hepatitis E virus.

  • It is transmitted by faecal-oral route, mainly via contaminated food (e.g. shellfish) or water. Foodborne transmission through consumption of raw or undercooked meat has been documented and HEV has also been detected in pig livers. However, the significance of this transmission route is uncertain. Person-to-person transmission appears to be less efficient than hepatitis A virus.

  • The incubation period range from 15 to 60 days with an average of 40 days.

  • Symptoms of acute hepatitis E resemble to other types of viral hepatitis, including jaundice, fatigue, abdominal pain and dark (tea colored) urine.

 

The disease is more common among adults than children and is more severe in pregnant women.

 

Prevention

 

At present, no vaccine is available for the prevention of hepatitis E. To prevent hepatitis E infection, adopt good hygiene practice at all stages of food preparation:

 

  • Personal hygiene – wash hands with soap before preparing or eating food and after going to the toilet.

  • Food hygiene – drink only boiled water. All food, especially seafood (e.g. shellfish), pork and pig offal should be carefully cleaned and thoroughly cooked. Avoid raw and undercooked food. Handle and store raw and cooked food separately to prevent cross-contamination.