Rapid tests for hepatitis B

About hepatitis B

Hepatitis B is a viral infection of the liver caused by the hepatitis B virus (HBV). More than two billion people have been infected worldwide making it a serious global health problem. Approximately 360 million people suffer from chronic HBV infection and more than 520,000 die each year. About 50,000 of these deaths are from acute hepatitis B and 470,000 are from either cirrhosis or liver cancer.

When a person is first infected with the hepatitis B virus, this is called an acute infection. Symptoms include jaundice, fatigue, abdominal pain, loss of appetite, nausea, vomiting, and joint pain. Most adults, 90% to 95%, recover from the initial infection, but if the virus remains in the blood for more than six months, that person is classified as having a chronic infection. Unfortunately, 90% of infants and up to 50% of young children infected with hepatitis B will not clear the virus and will develop a chronic infection. Many chronically infected people are asymptomatic or develop only mild symptoms; however, they are still infectious and able to spread the virus to the unvaccinated.

In adult populations, HBV transmission occurs primarily among unvaccinated adults with high risk factors. The most important of these are heterosexuals with multiple sex partners, men who have sex with men, a history of other sexually transmitted infections, injection-drug users, and their sexual partners. There is also a high infection rate among those with prolonged household contacts and sex partners of those with chronic HBV infection. HBV is transmitted by direct contact with body fluids. This may occur either percutaneously (skin punctures or otherwise broken skin) or by contact with mucosal membranes. Some avenues of infection include contaminated needles or medical instruments, transfusion with contaminated blood or blood products, unprotected sex, and from neonatal/congenital infections.

In 1981, the US Food and Drug Administration approved the first vaccine for hepatitis B. This vaccine was made from human blood products. Due to fears about possible infection from HIV and other diseases, this vaccine was discontinued in 1990 and is no longer available in the United States, but is still available in other countries. In 1986, a hepatitis B vaccine produced from recombinant DNA technology was licensed, and a second recombinant-type hepatitis B vaccine was licensed in 1989.

The hepatitis B vaccines currently used in the United States are manufactured using yeast-based DNA recombinant technology and contain no human or animal products. It is impossible get hepatitis B from these vaccines since they composed of portions of the virus coat and contain no whole viruses.

The hepatitis B vaccine is an intramuscular injection that is generally administered as a three-dose series on a 0, 1, and 6 month schedule. There are also a number of vaccines designed to prevent HBV and one or more other infectious diseases, such as the hepatitis A virus (HBA) and HBV combination vaccine and the HBV, diphtheria, tetanus, and acellular pertussis (DTaP), and inactivated polio vaccines.

We have more information on our Hepatitis B virus biology page.

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