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Hello, my name is
Dr. Marco Antonio Olivera Martinez.
I am an Associate Professor
of Medicine
in the division
of Gastroenterology & Hepatology
at the University
of Nebraska Medical Center
in Omaha, Nebraska, United States.
I am the Associate Program Director
for the Transplant Hepatology
Fellowship.
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So what we're gonna
talk about in this slide is
the structure
of the hepatitis B virus.
This virus is known
as being a DNA virus.
This is the only hepatotropic virus
that has DNA
in its genetic material.
It's known to be part of the family
of the hepadnavirus group.
The genome of this virus
is approximately 3.2 kilobases
and it has the ability
to conform particle of DNA
that is called cccDNA,
ccc standing for circular, close,
and covalent DNA.
The peculiarity of this portion
of genetic material
is that the virus can insert it
into the host's DNA
and from there,
its capability of producing
break for replication
once the patient develops
immunity to this agent.
There are eight known genotypes
of the hepatitis B virus
and they are classified
A, B, C, D, E, and H.
The antigens that we know
that the virus produces
are named s, e, and core.
The s antigen is known
as the surface antigen.
And this is the first particle
that is synthesized by the virus
as it confers the protection
in the surface of the variant,
so the virus can go
from cell to cell
or be alive in the blood stream.
The e and the core antigens
are particularly present
when the virus
is actively replicating.
From
the epidemiological standpoint,
240 million people
have chronic infection
by hepatitis B in the world.
Defining chronic hepatitis B
as a presence
of a positive surface antigen
for more than six months
according to the World Health
Organization definition.
And the prevention
of this infection
is carried out
by a recombinant vaccine
that is available worldwide.
