What is hepatitis B?
Hepatitis B is a liver disease caused by the hepatitis B virus (HBV). Since 1991 when children started getting routinely vaccinated for the virus, cases of hepatitis B in the U.S. have gone down
What is hepatitis B?
Hepatitis B is a liver disease caused by the hepatitis B virus (HBV). Since 1991 when children started getting routinely vaccinated for the virus, cases of hepatitis B in the U.S. have gone down 82 percent, according to the Centers for Disease Control and Prevention.
HBV spreads through blood, saliva, or other bodily fluids. The most common way children become infected with hepatitis B is if they are born to a mother with the virus. Older children can become infected through injection drug use or unprotected sex.
There are two phases of hepatitis B: acute and chronic.
Acute hepatitis B is often a mild or asymptomatic illness that may clear on its own in a matter of weeks. The younger the patient, the less likely the virus will be cleared on its own, and the more likely the infection will become chronic. Children and adults who are not able to clear an HBV infection within six months are considered to have chronic hepatitis B.
Chronic hepatitis B may be a serious illness that can cause long-term health problems. Over time, the liver may remain healthy or may develop progressive scarring, leading to cirrhosis. Chronic hepatitis B is the most common cause of liver cancer in the world.
Over the course of decades, chronic hepatitis B progresses through four stages — immune tolerance, immune clearance, inactive (latent), and reactivated — based on the behavior of the virus and how the child’s immune system responds against it. The inactive carrier phase can last for years, often well into adulthood.
What is the liver, and what does it do?
The liver is the second largest organ in the body, located in the abdominal cavity. The liver helps the body in many ways:
- the liver produces proteins that allow blood to clot normally, transport oxygen, and support the immune system
- it produces bile, a substance that helps digest food
- it stores extra nutrients
- it hel