HEPATITIS B
Hepatitis B is an infectious illness caused by hepatitis B virus (HBV) which infects the liver of hominoidea, including humans, and causes an inflammation called hepatitis. Hepatitis B virus is an hepadnavirus—hepa from hepatotrophic and dna because it is a DNA virus and it has a circular genome composed of partially double-stranded DNA. The viruses replicate through an RNA intermediate form by reverse transcription, and in this respect they are similar to retroviruses. Although replication takes place in the liver, the virus spreads to the blood where virus-specific proteins and their corresponding antibodies are found in infected people.
The acute illness causes liver inflammation, vomiting, jaundice and rarely, death. Chronic hepatitis B may eventually cause liver cirrhosis and liver cancer—a fatal disease with very poor response to current chemotherapy.
Causal Organism: hepatitis B virus
Symptoms:
Many people who become infected with HBV experience mild symptoms or no symptoms at all, but they may still carry the infectious virus and pass it on to others. Symptoms may include:
- A short, mild, flu-like illness;
- nausea, vomiting and diarrhea;
- loss of appetite;
- weight loss;
- jaundice (yellow skin and whites of eyes, darker yellow urine and pale faces);
- itchy skin.
If a person lives with hepatitis B infection for a number of years then they may develop the following complications:
- chronic hepatitis
- liver cirrhosis
- liver cancer
Prevention and Cure:
Hepatitis B is transmitted through body fluids; prevention is thus the avoidance of such transmission: unprotected sexual contact, blood transfusions, re-use of contaminated needles and syringes, and vertical transmission during child birth. Infants may be vaccinated at birth.
In addition to these preventions, there are some drugs available for the treatment of the disease
· Alfa Interferon (Brand names: INTRON A, INFERGEN, ROFERON): Interferon is an antiviral agent with antiproliferative and immunomodulatory agent that is administered by subcutaneous injection
· Lamivudine (Epivir-HBV, 3TC): inhibits hepatitis B viral DNA synthesis.
· Baraclude (Entecavir): is the latest drug approved by the FDA for treatment of chronic hepatitis B. It works by inhibiting the function of Hepatitis B virus polymerase.