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What is Hepatitis B?

What is Hepatitis B? Hepatitis B is an infection by a virus, mostly found in the liver: the hepatitis B virus (HBV). This virus can be easily transmitted to others. Hepatitis B infection can become a chronic infection. Worldwide, 240 million are chronically infected with HBV, most of them in Asia and sub-Saharan Africa. Chronic infection means that the virus continues to replicate in the liver for more than 6 months, causing the death of liver cells (hepatocytes), inflammation and fibrosis. Hepatitis B infection can lead to liver cirrhosis and/or liver cancer (hepatocarcinoma). In infants, acute infection after contamination is usually not recognized as there are no symptoms but it usually leads to chronic infection. In adults who are not immunized, acute Hepatitis B can occur within months following contamination. It can be symptomatic (fever, jaundice, fatigue) and, exceptionally, cause death. In 95% of cases, it recovers but in 5% is followed by chronic infection.

Transmission The Hepatitis B virus is easily transmitted to a non-immunized person through mucosa contact with infected blood, semen and other body fluids. It seems most commonly transmitted in the following circumstances:

  • Birth, especially during delivery (transmission from an infected mother to her infant)

  • During sex activities with an infected partner

  • Sharing needles, syringes, or any injection equipment which has been in contact with infected blood

  • Sharing instruments such as razors or toothbrushes with an infected person

  • Exposure to infected blood (wound from sharp instruments, needle sticks, sharing syringes, needles or other equipment contaminated with infected blood)

HBV may survive around 7 days out of the body and could remain contagious during this time.

Prevention A vaccine against hepatitis B is available since the early 1980’s. It is cheap and extremely effective in preventing infection. ​WHO recommends “universal immunization”: for all infants, first dose at birth, followed by two doses within the first 6 months of life. Immunization of older children and adults consists of three doses at appropriate intervals.

Treatment Chronic hepatitis B infection can be treated with oral antiretroviral agents. Treatment can prevent the consequences of the liver infection, such as progression to cirrhosis and liver cancer but usually cannot definitely stop viral replication. Thus, the treatment cannot be interrupted because viral replication would resume.

There are free and anonymous testing and counselling appointment for HIV, Hepatitis B, Hepatitis C and Syphilis in Chiang Mai and Chiang Rai. Learn more on our contact page.

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