Originally known as serum hepatitis, 
Hepatitis B has only been recognized as such since 
World War II, and has caused current 
epidemics in parts of 
Asia and 
Africa. Hepatitis B is transmitted thorough sexual contact, and by injections transporting a 
virus-bearing serum[?], most often during 
blood transfusion and by contaminated 
needles and 
syringes.
Roughly 16-40% of sexual partners of individuals with hepatitis B will be infected through sexual contact.
Hepatitis D infection requires a concommittant infection with hepatitis B.
Hepatitis B infection can  lead to a chronic inflammation of the liver, leading to cirrhosis. This type of infection dramatically increases the incidence of liver cancer.
A recombinant vaccine to prevent hepatitis B is available.
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