Hepatitis B: Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus. It is a major global health problem. It can cause chronic infection and puts people at high risk of death from cirrhosis and liver cancer.Symptoms: Most people do not experience any symptoms during the acute infection phase. However, some people have acute illness with symptoms that last several weeks, including yellowing of the skin and eyes (jaundice), dark urine, extreme fatigue, nausea, vomiting and abdominal pain.
Causes: Hepatitis B spreads in several ways. You can get it from sex with someone who's sick or by sharing a needle when using street drugs. The virus also can pass from a mother to her newborn child at birth or soon afterward. Most adults with hepatitis B get better, but a small percentage can't shake the disease and become carriers, which means they can spread it to others even when their own symptoms disappear.
Diagnosis: A number of blood tests are available to diagnose and monitor people with hepatitis B. Laboratory diagnosis of hepatitis B infection focuses on the detection of the hepatitis B surface antigen HBsAg. Acute HBV infection is characterized by the presence of HBsAg and immunoglobulin M (IgM) antibody to the core antigen, HBcAg. The presence of HBeAg indicates that the blood and body fluids of the infected individual are highly contagious.
Treatment: care is aimed at maintaining comfort and adequate nutritional balance, including replacement of fluids lost from vomiting and diarrhoea. Chronic hepatitis B infection can be treated with drugs, including oral antiviral agents.Statistics: The number of hepatitis B virus (HBV)-infected persons in Japan is estimated to be 1 million, or 0.8% of the total population. HBV is classified into eight genotypes, A to H, by their differences in genome sequences. Circulating genotypes in Japan differ according to geographical region, with the prevalent genotypes in 2001 being C (84.7%) and B (12.2%), while A (1.7%) and D (0.4%) were less frequent.