About HBV

Chronic Hepatitis B (CHB) is a serious global health problem.¹ It is the 10th leading cause of death in the world.² CHB affects approximately 350 million people globally¹ and is responsible for up to 1.2 million deaths worldwide each year.² Up to 80% of the world’s primary liver cancer, which is currently the fifth most frequent cancer worldwide, is attributable to chronic CHB.²

The danger of HBV lies in its silent transmission and progression. Many people infected with HBV have no symptoms and can go undetected for many years.³ Such individuals may have normal blood tests for liver function and often feel healthy. CHB generally causes only mild, non-specific symptoms, so many people do not realize they are infected and at risk for serious liver disease until the liver disease is far advanced.

Transmission

Many people may not know that HBV is 50 to 100 times more infectious than the AIDS virus, HIV.¹ In highly endemic areas many people become infected when they are infants or young children.  Frequently, transmission of HBV occurs during the birthing process when the virus is passed on from the mother (who is often unaware that she is a carrier and has CHB) to her child.^1,4 This type of transmission, called vertical transmission, is the primary mode of transmission in Eastern countries. 

Other principle ways that the virus is transmitted include blood transfusions, sharing or re-using needles for injection or tattoos, and unprotected sex.⁵ This type of transmission, called horizontal transmission, is the primary mode of transmission in Western countries. 

Prevention

Vaccines are available for the prevention of hepatitis B. Although 147 countries worldwide have implemented routine HBV immunization programs, 10 percent of healthy children who receive the vaccine fail to develop protective antibodies to HBV.² Vaccines may also not be appropriate or beneficial for patients who are already infected.

Young children who become infected with HBV are most likely to develop chronic infection.¹ About 90 percent of infants infected during the first year of life and 30 to 50 percent of children infected between one to four years of age develop chronic infection.¹ The risk of death from HBV-related liver cancer or cirrhosis is approximately 25 percent for persons who become chronically infected during childhood.¹

1 World Health Organization. Hepatitis B Fact Sheet number 204.
2 Lavanchy, D. Journal of Viral Hepatology. 2004. Mar; 11(2):97-107
3 Centers for Disease Control, Frequently Asked Questions
4  Grob. P. et. al. Introduction to epidemiology and risk of hepatitis B. Vaccine. 1995
5 Centers for Disease Control and Prevention. Viral Hepatitis B Fact Sheet