HBV is a mostly double-stranded DNA virus in the Hepadnaviridae family. HBV causes hepatitis in human and related virus in this family cause hepatitis in ducks, ground squirrels and woodchucks. The HBV genome has four genes: pol, env, pre-core and X that respectively encode the viral DNA-polymerase, envelope protein, pre-core protein (which is processed to viral capsid) and protein X. The function of protein X is not clear but it may be involved in the activation of host cell genes and the development of cancer.
Hepatitis B is a serious public health problem that affects people of all ages in the United States and around the world. Each year, more than 240,000 people contract hepatitis B in the United States. A highly infectious virus that attacks the liver causes the disease. Hepatitis B virus (HBV) infection can lead to severe illness, liver damage, and, in some cases, death. It can take, on average, 60-120 days from the time of exposure for symptoms of hepatitis B infection to develop. However, only 50% of adults infected with hepatitis B ever show any symptoms, with symptoms occurring even less often in infants and children. Some people do become very sick after they have been infected with HBV.
Symptoms may include:
·Jaundice (yellowing of the skin and eyes)
·Dark-colored urine
·Light-colored bowel movements
·Flu-like feelings
– poor appetite, fatigue, weakness, nausea, or vomiting
·Fever, headache, or aching joints
·Skin rash or itchiness
·Pain in the upper right abdomen
·Intolerance to fatty foods and cigarettes
·Odd tastes and smells