* Hepatitis B is an infection of the liver caused by the hepatitis B virus (HBV). Hepatitis B may cause people to become very ill for several weeks.
* These patients may have jaundice (yellow skin), poor appetite, and other symptoms. A life-threatening hepatitis B infection is called 'fulminant,' although this occurs in only 1% of symptomatic cases. However, some people, especially children, appear to have almost no symptoms when they acquire hepatitis B. Hepatitis B is spread through exposure to infected blood or secretions.
* The body's immune system is eventually able to wipe out the virus and cure the infection in 95% of infected adults. Unfortunately, some patients' immune systems are unable to eliminate the virus and they become chronically infected. Children are especially prone to chronic infection, which occurs in 95% of newly-infected infants compared with 5% of newly-infected adults.
* Patients with chronic hepatitis B carry the virus for years and usually for life, allowing it to continue to cause inflammation and scarring in the liver. Advanced scarring of the liver is called 'cirrhosis.' If the cirrhosis is severe, it can affect the ability of the liver to function, and can lead to liver failure or death.
* People who are chronic carriers of HBV are also at risk for liver cancer. For these reasons, scientists have developed medications to help reduce the risk of complications in people who are chronically infected with HBV.
* It is important to note that there are effective vaccines available [haemophilus B/hepatitis B vaccine-injection (Comvax), hepatitis b vaccine-injection (Engerix-B, Recombivax-HB), Heptavax-B, Pediarix)] to prevent the infection in the first place. The vaccine is currently recommended for all children in the United States and for adults who are at increased risk for hepatitis B. Unfortunately, the vaccine does not help people who are already infected.