Final answer:
Hepatitis B is a viral infection that causes liver inflammation. It is transmitted through exposure to infectious blood or body fluids and is most common among intravenous drug users and individuals with multiple sexual partners. Chronic infections can lead to severe liver damage, but a vaccine is available for prevention.
Step-by-step explanation:
Hepatitis B is inflammation of the liver caused by infection with the hepatitis B virus (HBV). It can be transmitted through exposure to infectious blood or body fluids such as semen or saliva. The virus can be spread through skin puncture, placental transmission, or mucosal contact, but not through casual contact like hugging or hand holding. Those at highest risk of infection include intravenous drug users, individuals with multiple sexual partners, and healthcare workers treating infected patients. Chronic infections of HBV can lead to cirrhosis or liver failure and are more common in infants. Vaccination is available for children as part of the standard vaccination schedule and is recommended for adults at greater risk. It is also required for healthcare workers with occupational exposure to blood or infectious materials.