The hepatitis B virus (HBV) which causes hepatitis B is a DNA virus from the Hepadnavirus family.
Disease
HBV is a hepatotrophic virus and causes an acute
hepatitis after an incubation period that ranges between six weeks and
six months. Following acute disease most people recover, the mortality
rate being about 1% in hospitalised patients. Presentation of infection
ranges from subclinical, which can be diagnosed only by laboratory
tests, to fulminant liver diseases with necrosis and death.
Mode of transmission
HBV is transmitted in the health care setting by
parenteral exposure to infected tissues, including blood or other body
fluids. The virus may also be transmitted by exposure of mucous
membranes, such as eyes, nose and mouth to infected material.
the risk of transmission of HBV following exposure to
the blood of an infected person ranges from 2% if HBV e antigen (HBeAg)
is absent, to 40% if HBeAg is present.
Standard precautions are sufficient to minimise the risk of transmission of HBV.
Significance in endoscopy
HBV is a highly infectious virus and high concentrations
of viral particles are found in the blood of symptomatic hepatitis B
sufferers and asymptomatic hepatitis b carriers, particularly those who
are HBeAg positive. Despite the high infectivity of hepatitis B, there
is only a single well-documented case of transmission of hepatitis B by
endoscopy.
Clinical studies following up patients who have been
endoscoped on the same endoscopy list as known hepatitis B positive
patients have prodiced no evidence of infection. Hepatitis B virus is
moderately sensitive to the majority of chemicals. However, failure to
remove blood, mucous and protein coagulums will inactivate some
chemicals. This means that the virus will be protected from the
chemical's action.
This video presentation is made to educate public about Hepatitis B
virus (HBV) that cause chronic liver infections and to promote Hep B
vaccination. There is no copyright. Use the video as you wish for the
common good.