Digestive Diseases and Hepatitis B
Hepatitis B (Hep B, HBV) is an inflammation of the liver causing scarring of the liver, liver failure, liver cancer and even death. Hepatitis B is caused by the hepatitis B virus or HBV and it is estimated that over 300 million people are infected worldwide.
According to the CDC, the number of people contracting hepatitis B has decreased from an average of 200,000 per year in the 1980s to 43,000 in 2007. The highest rate of infection occurs among those 20 to 49 years old. The infection can be transmitted through bodily fluids like vaginal secretions, semen, open sores or blood.
How does hepatitis B virus cause liver injury?
Hep B reproduces in liver cells but the virus alone is not the problem, the immune system is. The response triggered by the virus causes inflammation and serious injuries to the liver as the immune system tries to get rid of the virus. In most cases there are limited damages and the human body is capable to fight the infection off within a few months. After you are infected with HBV your body produces antibodies that will last for a lifetime so you won’t be infected with it again.
There are cases where the body can’t get rid of the infection and even if you don’t show any symptoms the virus is still there. In this situation you remain a carrier and your blood and bodily fluids can infect other people that come in contact with you through unprotected sex, open sores or any other ways. Right now, there are approximately 1.25 million carriers in the U.S.
If you are a carrier then your disease can follow two main routes: either it goes away after a while (medicine hasn’t figured out why yet) either it evolves into chronic hepatitis. If the hepatitis becomes chronic then the situation is pretty bad for the liver, as it can lead to cirrhosis and liver cancer, both deadly conditions.
Approximately 5% to 10% of adults and children older than age 5 with this infection can develop a chronic infection. These rates are even higher for children younger than age 5 (25% to 50%) or for infants infected at birth (90%).
What are the symptoms of Hepatitis B?
Only 30% to 50% of people infected with HBV show symptoms from the beginning. Early symptoms can be confused with those of the flu: fever and joint pains. The symptoms that are most specific to Hepatitis B are:
- yellow skin and yellowing of the white part of the eyes;
- brown or orange color of the urine;
- unexplained fatigue that lasts for a long period of time;
- loss of appetite, nausea, vomiting;
- abdominal pain;
Still, for many people none of these symptoms show and the disease is discovered only through a blood test. The first stage of a HBV infection is called acute hepatitis and rarely, it can be fatal for the liver. There were cases of acute hepatitis when the liver was damaged so badly that the patient went into a coma due to liver failure. This condition is called “fulminant hepatitis” and patients having it should be evaluated for liver transplantation.
What determines the levels of injuries the liver is going to sustain?
The major determinant of the liver situation is our own immune system. People who develop a strong immune response are more likely to get rid of the virus and recover but they are also more likely to develop severe livery injury and strong symptoms. A weaker immune response may protect the liver for the moment and develop fewer symptoms but there is also a higher risk to develop chronic hepatitis.