The infection is caused by a virus of hepatitis B (HBV virus). It is a potentially dangerous and widespread disease, the numbers of infected are counted in hundreds of millions worldwide. The virus is transmitted by body fluids, i.e. during sexual intercourse or by sharing needles among intravenous drug addicts. Relatively common is also transmission from a sick pregnant woman to the fetus. It is possible to get infected by contaminated blood transfusion or by dialysis, but this is extremely rare in developed countries.
Note: The infection may occur together with hepatitis D.
The first signs if infection may occur in 1-3 months after the infection – the incubation period is quite long. First manifestation is related to acute inflammation of the liver tissue – nausea, loss of appetite, vomiting and diarrhea. Jaundice is also a typical sign, but it is not present in all cases. After the acute phase, the majority of people undergo full recovery and their body disposes of the viral particles. Very rarely, the infection has a dramatically quick progress that is accompanied with rapid deterioration of liver functions and acute liver failure.
In children and in people with weakened immune system, the organism is unable to fully handle the infection, which turns into chronic liver inflammation. This chronic inflammation may be asymptomatic, or it may cause only unspecific digestive problems. However, some people suffering from chronic hepatitis B are threatened by liver cirrhosis and liver cancer.
Clinical symptoms may be suspicious, especially inpatients with risky behavior (promiscuous sexual behavior, unprotected sex, intravenous drug abuse, etc.). Blood tests show elevation of liver tests marking the liver damage. Serology can confirm the diagnosis by finding specific viral antigens and antibodies directed against the virus in the patient’s blood. Signs of liver cirrhosis and its complications can be found by abdominal ultrasound.
The prognosis depends on the behavior of the virus. The majority of people undergo classic acute hepatitis that is followed with a quick recovery. The prognosis of such patients is excellent. The prognosis of patients with chronic form of the disease that has progressed into cirrhosis is serious as they are threatened by its complications.
There is an effective vaccine, which is in many countries part of the compulsory vaccination program. When this is not possible, it is advisable to vaccinate at least professions with high risk of being infected (medical personnel, patients in chronic dialysis program, etc).
It is necessary to treat patients with chronic HBV infection, which damages liver tissue. There is a number of special antivirotic medications, probably the most known is pegylated interferon. Although current methods can not completely cure the infection, many patients are able to induce long-term remission status (i.e. condition without clinical or laboratory signs of infection). Liver transplant is indicated in patients with severe liver damage and signs of liver failure non-responding to conservative therapy.