Hepatitis B: Difference between revisions
Created page with "Hepatitis B virus is a DNA virus. It can cause both acute and chronic hepatitis. It's usually prevented by a childhood vaccine. Treatment exists for chronic hepatitis B. == Etiology == HBV is very infective, 50 – 100 times more infective than HIV. Like hepatitis C and D, transmission usually occurs due to: * Parenteral ** IV drug users ** Health care personnel * Sexual (esp. men who have sex with men) * Perinatal == Clinical features == Hepatitis B can cause both ac..." |
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Hepatitis B virus is a DNA virus. It can cause both acute and chronic hepatitis. It's usually prevented by a childhood vaccine. Treatment exists for chronic hepatitis B. | '''Hepatitis B virus''' is a DNA virus. It can cause both acute [[viral hepatitis]] and chronic hepatitis. It's usually prevented by a childhood vaccine. Treatment exists for chronic hepatitis B. | ||
== Etiology == | == Etiology == | ||
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* Parenteral | * Parenteral | ||
** IV drug users | ** [[IV drug use|IV drug users]] | ||
** Health care personnel | ** Health care personnel | ||
* Sexual (esp. men who have sex with men) | * Sexual (esp. men who have sex with men) | ||
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For acute hepatitis, about 30% of persons are asymptomatic. Symptomatic persons generally have jaundice and nonspecific symptoms like fatigue and anorexia. | For acute hepatitis, about 30% of persons are asymptomatic. Symptomatic persons generally have jaundice and nonspecific symptoms like fatigue and anorexia. | ||
Chronic hepatitis occurs more frequently in children than adults. It’s usually asymptomatic, but problematic because it can cause chronic liver disease and hepatocellular carcinoma. | Chronic hepatitis occurs more frequently in children than adults. It’s usually asymptomatic, but problematic because it can cause chronic liver disease and [[hepatocellular carcinoma]]. | ||
== Microbiology == | == Microbiology == | ||
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Acute hepatitis B requires no treatment. | Acute hepatitis B requires no treatment. | ||
Chronic hepatitis B is treated with pegylated interferon or nucleoside analogues like entecavir or tenofovir. | Chronic hepatitis B is treated with pegylated [[interferon]] or [[Nucleoside analogue|nucleoside analogues]] like entecavir or tenofovir. | ||
== Prevention == | == Prevention == | ||
Latest revision as of 13:42, 27 October 2023
Hepatitis B virus is a DNA virus. It can cause both acute viral hepatitis and chronic hepatitis. It's usually prevented by a childhood vaccine. Treatment exists for chronic hepatitis B.
Etiology
HBV is very infective, 50 – 100 times more infective than HIV. Like hepatitis C and D, transmission usually occurs due to:
- Parenteral
- IV drug users
- Health care personnel
- Sexual (esp. men who have sex with men)
- Perinatal
Clinical features
Hepatitis B can cause both acute and chronic hepatitis.
For acute hepatitis, about 30% of persons are asymptomatic. Symptomatic persons generally have jaundice and nonspecific symptoms like fatigue and anorexia.
Chronic hepatitis occurs more frequently in children than adults. It’s usually asymptomatic, but problematic because it can cause chronic liver disease and hepatocellular carcinoma.
Microbiology
The virus consists of the so-called Dane particle and the coat and free particles. The Dane particle contains the virus core, the core antigen (HBcAg), and the e antigen (HBeAg). The coat and free particles contain the surface antigen (HBsAg).
Diagnosis and evaluation
Diagnosis is based on serology, including anti-HBs, anti-HBc, and anti-HBe, and detection of the two HBV antigens, HBeAg and HBsAg.
- HBsAg – general marker of HBV infection
- HBeAg – marker for infectiveness (indicates replicating virus)
- HBV-DNA – marker for infectiveness (indicates replicating virus)
- Anti-HBs – general marker of immunity
- Anti-HBc IgM – marker of acute infection
- Anti-HBc IgG – marker for past or chronic infection
In acute infection, HBsAg, HBeAg, and IgM anti-HBc are present. Seroconversion from HBsAg to anti-HBs indicates resolved infection.
In chronic infection, HBsAg and IgG anti-HBc are present.
In a vaccinated person, anti-HBs alone is present.
Treatment
Acute hepatitis B requires no treatment.
Chronic hepatitis B is treated with pegylated interferon or nucleoside analogues like entecavir or tenofovir.
Prevention
HBV can be prevented by vaccine. The vaccine is part of the childhood vaccination programme and is given right after birth (in Hungary) or at 3 months (in Norway). For those who were not vaccinated in childhood, the vaccine is recommended for those at high risk, like health care workers, and teenagers.
Passive immunization (HBIG) is used as post-exposure prophylaxis and must be given within 48 hours.