Hepatitis B

Hepatitis B: Description

Hepatitis B is an infectious disease of the liver that is caused by a Hepadnaviridae-family DNA virus, the hepatitis B virus (hereafter referred to as HBV). Acute HBV infection heals in more than 90 percent of adult cases without treatment, but in 5-10 percent of cases it becomes a chronic infection. In a subset of patients with chronic HBV infection the disease takes a severe course, evolving into cirrhosis of the liver with complications such as bleeding from varicose veins of the esophagus (esophageal varices hemorrhage), abdominal dropsy (ascites) or hepatocellular carcinoma. Hepatitis B is the most common viral hepatitis worldwide, and is transmitted both parenterally (blood, blood plasma) as well as sexually. Vaccination is among the most important preventive measures.

Hepatitis B: Symptoms

In most cases the disease develops without specific clinical indications. The incubation period can be between 30 to 180 days. Acute hepatitis B can be accompanied by nonspecific symptoms such as fatigue, loss of appetite, food intolerance, nausea, vomiting, light-colored stools, dark urine, mild fever or muscle and joint pain, up to jaundice. The chronic form of the disease is usually asymptomatic, but in rare cases fatigue, lethargy, and flu-like symptoms such as joint and muscle pain may occur. Only later can complications arising from cirrhosis of the liver occur (hemorrhage from varicose veins of the esophagus, abdominal dropsy, hepatocellular carcinoma).

Hepatitis B: Causes and Risks

The disease is caused when the subject is infected with the hepatitis B virus. Unprotected sex is considered a big risk factor, as well as intravenous drug use, or using contaminated implements during tattooing or piercing. The virus can also be transferred at birth to the newborn, therefore the children of HBV-infected mothers must be actively and passively vaccinated immediately at birth.

Hepatitis B: Examination and Diagnosis

After a blood sample is taken, the blood will be tested within the scope of hepatitis B serology for HBV antibodies, its proteins (antigens) and viral DNA. This investigation can determine whether an acute, chronic or fully cured HBV infection exists. An ultrasound examination can determine whether the liver has already undergone restructuring. In a so-called FibroScan examination the hardening of the liver can be assessed. The possible causes and extent of liver damage can be assessed through a liver biopsy.

Hepatitis B: Treatment

Alongside interferon-alpha therapy, there are new drugs available - the so-called "nucleoside/nucleotide analogs" - which are taken in tablet form. Entecavir and Tenovofir, among others, are very effective, biocompatible drugs that are approved for the treatment of chronic hepatitis B. However, these are typically taken as part of long-term therapy.

Hepatitis B: Course and Prognosis

Although a complete cure of chronic hepatitis B is not possible, the therapy described above can significantly reduce the risk of cirrhosis of the liver and hepatocellular carcinoma. In most cases, chronic hepatitis B causes little discomfort. In about 20 percent of patients with long-standing untreated hepatitis B, cirrhosis of the liver or hepatocellular carcinoma may result. In a few cases, such as in very advanced stages of chronic hepatitis B or in the event of liver failure, liver transplantation is one of the latest treatment options.