HEPATITIS B

Hepatitis B is one of the major diseases of mankind, and is now preventable with safe and effective vaccines. Out of the 2,000 million people who have been infected with the virus, more than 350 million are chronic carriers of the virus. These chronic carriers are at high risk of death from cirrhosis of the liver and liver cancer, diseases that kill about one million persons each year.

Although the vaccine will not cure chronic carriers, it is 95% effective in preventing the carrier state from developing, and is the first vaccine against a major human cancer. The World Health Organization has called for all children to receive this vaccine, and 100 countries have added it to their routine immunization programmes. However, the children in the poorest countries, who need the vaccine the most, are not receiving it because their governments cannot afford it. This is medically and morally unacceptable, and is the major problem to be solved before we can control this disease on a global basis.

What is Hepatitis?

Hepatitis means inflammation of the liver, and the most common cause is infection with one of 5 viruses, called hepatitis A, B, C, D, and E. All of these viruses can cause an acute disease with symptoms lasting several weeks including yellowing of the skin and eyes (jaundice), dark urine, extreme fatigue, nausea and vomiting, and abdominal pain. It can take several months to a year to feel fit again. Some of these viruses can cause a chronic carrier state in which the patient never gets rid of the virus, and many years later develops cirrhosis of the liver or liver cancer. Hepatitis B is a virus of this type and the most serious type of viral hepatitis. It is also the only type causing chronic disease for which a vaccine is available.

Who gets hepatitis B?

Most people in much of the developing world (sub-Saharan Africa, most of Asia, and the Pacific) become infected with the virus during childhood, and 8% to 15% of people in the general population become chronic carriers. In these regions liver cancer caused by hepatitis B is the number one or two cause of cancer death in men. High rates are also found in the Amazon and the southern parts of Eastern and Central Europe. In the Middle East and the Indian sub-continent, about 5% of people are carriers. Infection is less common in Western Europe and North America, where less than 1% are chronic carriers.

How do people get hepatitis B?

Hepatitis B is transmitted by blood and close personal contact, much like AIDS, but hepatitis B is 50 to 100 times more infectious than AIDS. In developing countries newborns may be infected if their mother is a chronic carrier. Unlike AIDS, the virus is transmitted within households between young children. Injections with reused unsterilized needles and syringes is another important route. In many developing countries almost all children become infected with the virus, and the younger they are, the more likely they will become a chronic carrier. This is also why we need to use the vaccine in young children in most of the world.

In Western Europe and North America, the pattern of transmission is different. Although there is still some transmission from carrier mother to child, most of this is prevented because all pregnant women are screened to detect hepatitis B infection, and babies are treated at birth with vaccine and other medicines. Most transmission in these countries occurs during young adulthood due to sexual activity, needle sharing, occupational exposure, travel, or being in an ethnic group from a country with high rates of infection. Hepatitis B is the major infectious occupational hazard of health workers, and most health care workers have received hepatitis B vaccine. Hepatitis B is not spread by contaminated food or water, and cannot be spread casually in the workplace.

Can chronic hepatitis B and liver cancer be treated?

Liver cancer is almost always fatal, and usually develops between the age of 35 and 65 years of age, when people are maximally productive and are trying to raise their own children. The loss of a mother or father in a developing country can devastate the entire family. In developing countries most people die within months of diagnosis. In industrial countries surgery and chemotherapy can prolong life up to a few years. Chronic hepatitis in some patients is treated with a drug called interferon which can help some patients. However, interferon therapy costs thousands of dollars and will never be available to most patients in developing countries. Patients with cirrhosis are sometimes given liver transplants, with varying success. It is much preferable to prevent this disease with vaccine than to try and cure it.

How safe and effective is the vaccine?

Hundreds of millions of people have received this vaccine, which became available in 1982, and has an outstanding record of safety and effectiveness. Studies have shown that the vaccine is 95% effective in preventing children or adults from developing the chronic carrier state if they have not yet been infected. In many countries where 8% to 15% of children used to become chronic carriers, this has been reduced to less than 1% in immunized groups of children. Other studies have shown a direct reduction in liver cancer in immunized children. It is important to realize that this is the first vaccine against a major human cancer.

How is WHO trying to control hepatitis B?

In 1991 WHO called for all countries to add hepatitis B vaccine into their National Immnization Programmes, and so far 100 countries have done so. This includes all industrial countries in Western Europe, North America, and Australia, with the exception of the Scandanavian countries, the Netherlands, and the UK and Ireland. Fortunately, most countries in Eastern Asia and the Middle East use the vaccine, but it is not used in many countries in sub-Saharan Africa, the Indian subcontinent, and in the Newly Independent States. The poorest countries in the world cannot afford this vaccine, and their children are unprotected. The cost vaccine to immunize a child with hepatitis B vaccine in a developing country is about 3 Swiss franks, the cost of a bottle of mineral water in a Geneva cafe. We need to raise the awareness of donor agencies that buy vaccines for the poorest developing countries so that they will begin to supply the vaccines, especially in Africa.

For further information, contact WHO's Office of Public Information, Geneva. Telephone (41 22) 791 2584. Fax (41 22) 791 4858. E-Mail: inf@who.int

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