according to the terminal drop hypothesis

During this time, the virus can still cause infection if it enters the body of a person who is not protected by the vaccine. The hepatitis B virus can survive outside the body for at least 7 days. This is the basis for strengthening and prioritizing infant and childhood vaccination. Hepatitis B infection acquired in adulthood leads to chronic hepatitis in less than 5% of cases, whereas infection in infancy and early childhood leads to chronic hepatitis in about 95% of cases. Sexual transmission is more prevalent in unvaccinated persons with multiple sexual partners. Transmission of the virus may also occur through the reuse of contaminated needles and syringes or sharp objects either in health care settings, in the community or among persons who inject drugs. Hepatitis B is also spread by needlestick injury, tattooing, piercing and exposure to infected blood and body fluids, such as saliva and menstrual, vaginal and seminal fluids. The development of chronic infection is common in infants infected from their mothers or before the age of 5 years. In highly endemic areas, hepatitis B is most commonly spread from mother to child at birth (perinatal transmission) or through horizontal transmission (exposure to infected blood), especially from an infected child to an uninfected child during the first 5 years of life. Sixty million people are infected in the WHO Eastern Mediterranean Region, 18 million in the WHO South-East Asia Region, 14 million in the WHO European Region and 5 million in the WHO Region of the Americas. The burden of hepatitis B infection is highest in the WHO Western Pacific Region and the WHO African Region, where 116 million and 81 million people, respectively, are chronically infected. Preventing hepatitis B infection averts the development of complications including chronic disease and liver cancer. It can cause chronic infection and puts people at high risk of death from cirrhosis and liver cancer.Ī safe and effective vaccine that offers 98% to 100% protection against hepatitis B is available. Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus (HBV).

According to the terminal drop hypothesis