WHAT IS HEPATITIS?
In simple terms, hepatitis is an inflammation of the liver. It can be caused by viral (for example, type A, B, C, D, E, F and several others), bacterial or protozoan infections. Toxic chemicals, drugs and alcohol may also damage the liver, leading to hepatitis. During the past several years, effective vaccines have become commercially available against the most common causes of viral hepatitis, types A and B.

What are the symptoms?
The symptoms of viral hepatitis are often vague, such as fatigue and malaise. Some, however, develop a more severe illness, with symptoms such as:
- Loss of appetite
- Jaundice (yellow skin and eyes)
- Dark urine
- Pale feces
- Fever, chills, muscle and joint aches, which make you, think you have the flu
- Nausea and sometimes vomiting
- Pain and swelling of the upper right side of the abdomen (where the liver is)
- Weight loss

WHAT IS HEPATITIS B?
Hepatitis B is one of at least five viral strains of hepatitis that affect the liver. Hepatitis B is one of the most serious viral strains because of the possibility of severe complications, such as massive liver cell death (cirrhosis) and a strong association with liver cancer (hepatoma).
After an individual is exposed to the virus, between 6 weeks and 6 months may elapse before signs and symptoms of the infection, sufficient to make a diagnosis, appear. Complete recovery may take 6 months or longer.

What are the possible effects of a hepatitis B infection?
The hepatitis B virus has been extensively studied. Among the consequences resulting from infection with this virus is:

- Most people recover completely from the disease and develop lifelong immunity.
- Some people infected with the hepatitis B virus do not form antibodies and the virus remains in their blood and liver. These persons become carriers of the hepatitis B virus, and can pass the disease to others. They also run the risk of developing liver cancer or cirrhosis 10-20 years later. Nearly half the family members of those suffering the acute illness may become infected.
- A high percentage of infected newborns become carriers. Many of these carriers will later (in adulthood) die of complications of liver disease due to the hepatitis B virus.
- Persons who have an acute or chronic hepatitis B infection are at high risk of simultaneously contracting Delta Agent infection. Delta Agent is a recently discovered virus that also infects the liver. Delta Agent replicates and causes liver injury only in persons who are acutely or chronically infected with the hepatitis B virus. Illness resulting from a combined Delta Agent-hepatitis B infection is usually more severe than that caused by hepatitis B alone.

Considering that there are estimated to be more than 350 million hepatitis B virus carriers in the world, of whom 170 million are Asians, with 45 million in Southeast Asia alone, the change of getting hepatitis B cannot be ignored.

How is hepatitis B virus spread?
An infected person has hepatitis B virus in his blood, saliva and semen, and may also have the virus in urine, feces and other secretions. You can get hepatitis B by:

- Sexual contact with an infected person.
- Being born of an infected mother.
- Accidental contact with an infected person's body fluids or secretions through skin cuts, bruises or mucosal membranes of the eyes and mouth.
- Using unsterilized instruments contaminated by an infected person, such as in injections, ear piercing, acupuncture, tattooing or dental procedures.
- Less common modes of contagion include sharing personal items with an infected person who may break the skin, such as a toothbrush, razor, comb or nail clipper.

There are usually no symptoms associated with infection in infancy, but a high percentage of infected babies become carriers for life.

WHAT IS HEPATITIS A?
Unlike hepatitis B, the hepatitis A virus is contracted primarily through food and water contamination. Inadequately cooked cockles are a frequent source of infection. Hepatitis A is endemic in Asia, Africa, the Middle East, Central and South America. Symptoms of the disease are similar to hepatitis B; however, long-term complications such as cirrhosis and liver cancer do not occur.

PREVENTION OF VIRAL HEPATITIS
The hepatitis B virus can be destroyed by treating the personal utensils of carriers with either boiling water or a household bleach such as Clorox. Hepatitis B may be prevented by immunization with the highly effective and well-tolerated vaccines that are now available. If you are planning a long stay or trip to an endemic region, it is advisable to be vaccinated against hepatitis B. Adults who grew up in an endemic region should have a blood test before vaccination to check for no previous exposure to the hepatitis B virus. Vaccination is not necessary for those previously exposed to the virus since they already are immune. Newborns and children should be vaccinated as early as possible.

The immediate benefits of vaccination will be protection from hepatitis B infection, Delta Agent infection, plus long-term potential benefits such as a marked reduction in the risk of liver cancer. Vaccination consists of three intramuscularly injections that are given in the upper arm (deltoid muscle) over the course of 6 months.

Side effects are uncommon, and may consist of local soreness at the site of injection, rashes, and tiredness and, occasionally fever. Since hepatitis A is transmitted primarily by infected food and water, prevention involves standard food and water precautions when traveling in regions with sub optimal sanitation. A highly effective vaccine against hepatitis A, will give protection within 2-4 weeks following injection. A second booster injection is recommended in 6-12 months, which will give long-term immunity (10 or more years).
Recently, a single vaccine combining both hepatitis A & B has become available. This allows fewer injections (only three instead of five).

Hepatitis C

Hepatitis C is becoming increasing important and its transmission is similar to hepatitis B. Presently, there is no commercially available vaccination against hepatitis C.