Symptoms
The possible symptoms of acute hepatitis include:
- Mild fever
- Dark urine
- Lack of appetite
- Nausea and vomiting
- Weakness, fatigue
- Abdominal pain
- Jaundice
- Swelling of the liver and spleen
However, hepatitis B can also be asymptomatic. From an acute infection, which lasts about two to four months, chronic hepatitis B can develop in a minority of patients (about 5%) after six months. Its complications include cirrhosis and severe liver diseases such as liver failure and hepatocellular carcinoma (liver cancer). Hundreds of millions of people worldwide are chronically infected, primarily in Africa, Asia, South America, Greenland, and Alaska.
Causes
The cause of the disease is infection with hepatitis B virus (HBV), a partially double-stranded DNA virus of the hepadnavirus family. Eight different genotypes (A to H) exist. An important drug target of the virus is the enzyme HBV DNA polymerase/reverse transcriptase. The virus is transmitted via blood, semen or other body fluids such as saliva. For example, during unprotected sexual intercourse and via used needles (drug abuse, tattoos, piercings). Mothers can pass the virus to the child at birth. The incubation period is about three months on average.
Diagnosis
Diagnosis is made by medical treatment based on the patient’s history, clinical presentation, laboratory methods (blood sampling, antigen and antibody detection), and liver biopsy.
Prevention
- Vaccines are available for drug prevention; see Hepatitis B vaccination.
- Protected sexual intercourse: use condoms, observe rules of conduct.
- Do not reuse syringes and needles
- Do not share razor blades and knives
Non-drug treatment
Liver transplantation may be necessary if liver damage is severe.
Drug treatment
Antiviral drugs are directly and causally effective against the viruses. They can be administered perorally. All agents are inhibitors of viral HBV DNA polymerase (reverse transcriptase inhibitors):
- Adefovir (Hepsera).
- Entecavir (Baraclude)
- Lamivudine (Zeffix)
- Telbivudine (Sebivo)
- Tenofovirdisoproxil (Viread)
- Tenofoviralafenamide (Vemlidy).
Interferons are substances produced naturally in the body with antiviral properties. They must be injected subcutaneously:
- Interferon alfa-2a (Roferon-A).
- Interferon alfa-2b (Intron-A)
- Peginterferon alfa-2a (Pegasys)
