Hepatitis B Virus (HBV) is a virus that contains DNA of the type Hepadnaviridae. The virus is present in most of the fluids of the individuals with acute and chronic hepatitis and in inactive carriers. It is transmitted parenterally, for example, as a result of sharing needles. It’s unlikely that there be oral transmission. Sexual contact is a frequent cause. The unvaccinated health professionals constitute a high-risk group for injury by needle prick. In areas where Hepatitis B is endemic, it is often transmitted from mother to baby which means vertical transmission or from direct contact which means horizontal transmission such as by scratching or biting.
The incubation time of HBV is 60 days and can vary between 28 to 160 days.
Approximately 30% of infections among adults are presented as icteric hepatitis and 0.1 to 0.5% develop fulminant hepatitis.
When fulminant hepatitis occurs, the immune response in infected hepatocytes is overwhelming and often there is no evidence of viral replication. The tests for HBsAg can be negative; hence the need for analysis for the detection of anti HBc (IgM).
Infection is resolved in> 95% of adults with loss of serum HBsAg and subsequently the appearance of anti-HBs. Natural immunity is characterized by detection of anti-HBc plus anti-HBs.
HBV infection leads to one of four outcomes: 1) Recovery after acute infection (> 95% in previously healthy adults <40 years old), 2) Fulminant hepatitis, 3) Chronic hepatitis B or 4) Idle carrier status.
Risk Factors And Transmission Groups of Adults At Risk of Acute HBV Infection:
- Healthcare professionals
- Police and military personnel
- Refugees and asylum seekers
- Tourists and students (unsafe sex)
- Any unsafe sex
- Injecting drug users
- Hemodialysis patients (always as carriers)
- People who receive unsafe injections
- People who receive not screened blood transfusions
- Unsafe procedures for piercing, tattoos, acupuncture, tribal scarification, circumcision.
- The reuse of injection equipment can cause up to 20 million of HBV infections per year.
How Do You Get Hepatitis B Virus?
HBV is transmitted through body fluids such as blood and semen, (breast milk and saliva are a controversial way). The way can be:
- Perinatal (mother to baby at birth) (vertical)
- From one child to another (horizontal)
- From unsafe injections and transfusions (parenteral)
- Non-sterile instruments, tattoo needles, dentistry equipment, and other sharp objects, for example: in the scarification, female circumcision.
- Sexual contact (sexual)
- Unprotected sex (whether heterosexual or homosexual)
HBV is transmitted either by skin pricking or mucosal contact with blood or other infectious bodily fluids. The virus is found in the highest concentrations in blood and serous exudates.
Hepatitis B Vaccination has been available since the early ‘80s and remains the most preferred way to prevent and deal with this infection. Hepatitis B can be prevented and universal vaccination is perhaps the best way to do so, espeially in countries where their prevalence is high. There are two types of Hepatitis B vaccines available.
Recombinant vaccines or those produced by genetic engineering are performed using HBsAg synthesized in yeast (saccharomyces cerevisiae) or in mammalian cells in which a gene has been inserted HBsAg. Both consist of a suspension of surface antigen HB. Each country has different preparations.
Vaccines derived from human plasma (VDP) are prepared from purified HBsAg from plasma from people with chronic HBV infection. There are more than 15 different VDPs licensed to world level.
There is no major difference between the two vaccines pertaining to efficacy and safety.
HBV vaccines generate protective levels (> 10 IU/ml) of antibodies against HBsAg in 95% of children and 90% of adults. Revaccination works in the 80% of people who did not respond to primary vaccination. Revaccination of non-responders is not recommended after two series of vaccinations (6 doses).
There are many ways to contract HBV; these are the parenteral route that occurs through needles, contaminated blood products, tattoos or acupuncture; also sexually, the vertical transmission which is mother-to-child transmission during childbirth and the horizontal transmission through non-sexual contact that occurs from objects in which the virus can remain stable up to 7 days.
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- Autoimmune Hepatitis or AIH: Causes, Types, Risk Factors, Symptoms, Diagnosis, Treatment, Complications
- Ischemic Hepatitis or Shock Liver: Causes, Symptoms, Treatment
- Hepandnavirus or Hepatitis B Virus
- How Hepatitis is Cured or Treated?