CHAPTER ONE
INTRODUCTION
1.1 INTRODUCTION TO HEPATITIS B
Viral hepatitis is a disease as old as the history of
Medicine. Hepatitis was described in the Babylonian Talmud in the fifty century
BC, and was referred to by Hippocratic over 2000 years ago. Despite this
ancient knowledge, it was not until 1963, that the first human Repetitious
virus was isolated, Hepatitis B. This was followed quickly by the purification
of Hepatitis A in 1973, and more recently by the isolation of viruses C, D, E
and G. These viruses are known to infect the human liver (Anderson et al;
2001).
However, there are more than twenty other viruses,
which infect the human liver. These are not considered “Repatitis viruses” as
these other viruses tend to infect organs other than the liver more seriously’.
These include common viruses such as Cytomegalovirus (CMV), Mumps, Rubella,
Epstein-Barr virus (EBV) as well as rare ones such as Rassa fever and yellow
fever viruses.
Any infection that results in inflammation of the liver is called
Repatitis (Greek Repaticus, liver). Incidentally, not all “hepatitis” is caused
by viruses. “HEPATITIS” means “inflammation of the liver”, and can be caused
also by other types of infection (bacteria fungi etc); toxic drugs; poisons;
alcoholism and so on (Drexott etal; 2005).
But of interest is one Repatitis virus – one of the
most common infections diseases, causing an estimated 1.5millon deaths world
wide each year – Hepatitis B. Hepatitis B is caused by the Repatitis B virus
(HBV), a double – stranded circular DNA virus of complex structure. Hbv is
class ivied as an orthoropadnavirus within the family hepadnaviridae. HBV was
originally recognized as the age responsible or serum Repatitis the most common
form of partially transmitted viral Repatitis and an import cause of acute and
chronic infection of the liver. This why hepatitis b is some times called seum
Repatitis. The virus was formerly and anilines referred to as Australian
antigen. The reason being that it was first isolated room the blood of an
Australian aborogie and is associated with HBV. (procott et al 2005.
Hepatitis B remain one of
the major cause of human suffering in the world despite a through understanding
of its transmission and prevention. Serum form undivided infected with
hepatitis B contains three district antigen
particles: a spherical 22nm particle, a 42 nm spherical particle ( counting DNA and DNA polymer able) called the Dane particle, and tubular or filamentous
particles that vary in length. The small spherical and tubular particles are the unassembled component of the Dane
particle- the infective form of the virus. The unassembled particles. Contain
hepatitis B surface antigen (HBsAg) whose presence in the blood is
(a) an indicator of Repatitis B infection (b) the basis for the large scale
screening of blood for the hepatitis B virus, and (c) the basis for the first
vaccine for human use developed by recombinant DNA technology (Evans, 1997
The Hepatitis B virus is normally transmitted through
blood transfusion, contaminated equipment, drug users unsterile needles, or any
body secretion (saliva, soren, sweat, breast milk, urine) The virus also can pass from the blood of an
infected mother through the placenta to infect
the fetus. Each year an estimated 200, 000 people in Nigeria are
infected with Australian Antigen (HBV) about 1000 person die yearly from
hepatitis related cirrhosis and about 5000 die from HBV related liver cancer.
(HBV is second only to tobacco as a known cause of rumen cancer). Worldwide,
HBV infects over 200 million people (Schlesinger & Schlesinger, 2001). The
clinccal signs of Repatitis B vary widely, most cases are symptomless. However,
sometime fever, loss of appetite, abominal discomfort, nausea, fatigue, and
other symptoms gradually appear following an incubation period of 1 to 3
months. The virus infects liver Hepatic cells and causes liver tissue
degeneration and the release of liver associated enzymes (transaminases) into
the blood team. This is followed by jaundice, the accumulation of bilirubin (a
breakdown product of raemoglobin in the skin and other tissue with a resulting
yellow appears. The distinctive yellow jaundice the Hepatitis B usually imparts
to its victims skin has made it an rasity detectable disease through
recorded history. Frequently, acute hepatitis B in anicteric and symptomatic,
although acute liver failure may develop. The virus persists in about 10
percent of infected immouno compent adults, and in as many 90 percent of
infants infect peninatally depending on the ethnic group of the mother. About
350 million people worldwide are persistent carries of hepatitis B. actually
one in twenty infection results in chronic hepatitis, defined as persistent
hepatitis virus six mouths after the onset of the acute illness. Chronic HBV
infection can be entirely begin with normal liver blood tests (“Chronic Carrier
State”) or may be an aggressive inflammatory process (“Chronic active hepatitis”),
which can lead to severe scarring (“Cirrhosis).
Approximately 25 percent of all patients with chronic
hepatitis will progress to cirrhosis and about 20 percent of those with
cirrhosis will develop hepatocellular carcinoma. That is to say, the risk of
liver cancer (hepatoma) is high in cirrhosis caused by HBV.
Hepatocellular carcinoma is one of the most common cancers worldwide
(Seeger & manor; 2000)
During the first phase of chronicity, virus
replication continues in the liver and replicative intermediates of the viral
genome may be detected in DNA extracted from liver hiopsies. Makers of virus
replication in serum include HBVDNA (this indicated virus presence and
activity), DNA polymerize (determines the presence of HBVDNA in liver cell, and
a soluble antigen, hepatition.be antigen (HbeAG), which is secreted by
productively infected hepatocytes. In those infected at a very going age this
phase may persist for life but, more usually, virus levels decline over time.
Eventually, in most individuals, there is immune clearance of infected
hepatocytes associated with seroconverision low replication, the viral senome
may integrate into the chromosomal DNA of some hepatocytes and these cells may
persist and expand closely. Rarely , seroconversion to anti-HBs follows
clearance of virus replication but, more frequently, HBSAg persists during a
second phase of chronicity as a result
of the expression of integrated viral DNA.
VIRAL REPLICATION
With respect to replication of the HBV, the
fundamental process of viral infection
is the expression of the viral replication cycle in a rost cell. The steps for
the infection process involving HBV usually include the following:
Enter a host
–
contact
and enter susceptible cell.
–
Replicate
within the cell.
–
Sprea
d to adjacent cells.
–
Cause
cellular injury.
–
Engender
a host immune response
–
Be
either cleared from the body of the host, establish a presistnt infection , or
kill the host.
–
Be
shed back into the environment (prexote
it al; 2005).
VIRAL SPREAD
Mechanisms of viral spread very, but
the most roates include bloodstream. The presence of viruses in the blood is called VIREAMA>HBV is spread
through blood, body secretion, needles, placenta as well as sexually. This os
to say that transmission as through parental routes. Therefore, transmission of
HBV can occur from person to person
as a result of transfer of blood by any
prouder which breaks the skin or mucous members HBV spread mainly parentally,
in most cases seen in adults , HBs (Australian Antigen) has been
identified in almost every body fluid f infected persons- saliva tears semen,
cerebrospinal fluid, ascetic fluid, breast milk synovial fluid, gastric juice,
urine and rarely in faces. This disease is, therefore, a major occupational
hazard of medical personnel. It is commonly
seen in people who receive
multiple blood transfusion or blood product intravenous drug abusers,
homosexuals and the sexually promiscuous.
1.2
PURPOSE
OF STUDY
The need for study can never be over
emphases having considered the above, this study serves the following
purpose or objectives.
1.
To obtain a general view of the group of
individual affected whether children or adults.
2.
To
show circumstances which dispose to viral hepatitis and suggest means of
reducing the incidence.
3.
To
review the management of these patients with regards to vestigation done and
treatment.
4.
To
understand the complex or exorbitant nature of the structure of the hepatitis B
virus as well as the debilitating effect it has on the patient
5.
Also
compare and contrast primary data from this study with secondary from the
library
6.
To
how rate of progression to chronicity as well as make known the daily
activities that will not result in contacting HBV.
1.3
SIGNIFIGANCE
OF STUDY
This study done to known the existence
or widespread of this disease among patience in Nation Orthopedic Hospital
Enugu. Or to understand and show the prevalent Hospital in question .the
significance of this study can never be over emphasicum this is because in
developing countries such as HBV is indisputable essential in the life of that
country especially in their hospitals. Many children are infected by hepatitis
B virus at on early age a significant portion of apparently healthy individual
are chronic carriers of HBsAg, that is the Australia Antign. The
significance of this study is seen in the light of having a better knowledge
and understanding or better still widening our scope of the chronically and
pathogenically of HBV.
4.1
STATEMENT OF PROBLEM
A study of this nature surely must have
problem which result in it. Hepatitis B is a viral disease that is spread
through all body fluids, that is to say
that one can contact this disease by exchange to body fluid with infected person. Looking at our society and hospital there are
cases where by unscreened blood is
transfixed to a patient case of multiple sex
partner people having unprotected sex, making use of sharp objects
without any care. All these dispose to viral hepatitis B. and gives risk to a
study of such .
1.5
LIMITATON/ SCOPE OF STUDY
As a result of time factor, the scope
of this study was narrowed down to fit Witter the time limit. Due to this fact,
this study was lenicted only among
patients in National Orthopedic Hospital Enugu. There fore, the scope or the
delimitation, which infect in the area of coverage of this study is National
Orthopedic Hospital Enugu.
1.6
HYPOTHESIS
H0 Hepatitis B is prevalent among patients in National Orthopedic
Hospital
Enugu.
H1 HepatitisB is not prevalent among patients
in National
Orthopedic Hospital Enugu.