Hepatitis B is a serious liver disease,
caused by hepatitis B virus. The disease is transmitted through human body
fluids such as blood and serum. It is an alarming public health problem worldwide.
Its methods of transmission include through mother to baby (perinatal), sexual contact
and the use of improper injection techniques.
Epidemiology:
Prevalence
of chronic HBV infection continues to be high, ranging over 10% in some Asian
and Pacific countries. In the
Middle East and the Indian subcontinent, an estimated 2–5% of the general population is chronically infected. 0.5% in the United States and northern European
countries . The current global estimate of the number of HBV infected
individuals is 350 million.Out of these 25-30% Western would die as a
consequence of the infection.
Epidemiology in
Pakistan:
Pakistan
is highly endemic with HBV. With nine million people infected with
HBV. and its infection rate is on a steady rise. The reason may be the lack of proper health facilities, poor
economical status and less public awareness about the transmission of major
communicable diseases including HBV.
Hepatitis
B Virus:
Hepatitis
B is a DNA Virus of the hepadnaviridae family of viruses. It replicates
within infected liver cells (hepatocytes). These virions are 30-42 nm in diameter. The nucleocapsid encloses the viral DNA and a DNA
polymerase that has reverse transcriptase activity. 14 protein of the virion coat is termed surface antigen
or HBsAg. It is sometimes extended as a tubular tail on one side of the virus
particle. The surface antigen is generally produced in vast excess, and is
found in the blood of infected individuals in the form of filamentous and
spherical particles. Filamentous particles are identical to the virion tails –
they vary in length and have a mean diameter of about 22nm. The outer surface
coat surrounds an inner protein shell, composed of HBc protein (hepatitis-B
core protein) or HbcAg (hepatitis B core antigen). This inner shell is referred
to as the core particle or capsid. Finally, the core particle surrounds the
viral DNA and the enzyme, DNA Polymerase.
Signs and Symptoms:
Any common symptoms
that might show up, are usually flu-like symptoms, including fever,
fatigue, muscle or
joint pain. Severe symptoms include yellow eyes and skin called jaundice and a
bloated or swollen stomach. Symptoms may last several weeks or
months. The illness lasts for a few weeks and then gradually improves in most affected people. A few people may have
more severe liver disease and
may die as a result. The infection may be entirely asymptomatic and may go
unrecognized.Symptoms outside of the liver are present in 1–10% of HBV-infected people. And
include serum-sickness–like
syndrome, acute necrotizing vasculitis, membranous glomerulonephritis,
and papular
acrodermatitis of childhood . It is not possible, on clinical
grounds, to differentiate hepatitis B from hepatitis caused by
other viral agents and, hence, laboratory confirmation of
the diagnosis is essential. They can be used to distinguish acute from chronic
infections. Laboratory diagnosis of hepatitis B infection focuses on the
detection of the hepatitis B surface antigen HBsAg.
Mode of Transmission:
The hepatitis B
virus is carried in the blood and other body fluids. The virus is present in
the blood, saliva, semen, vaginal secretions, menstrual blood, and to a lesser extent,
perspiration, breast milk, tears and urine of infected individuals. The highly
resilient virus, is easily transmitted through contact with infected body
fluids. Hepatitis B is also spread
by percutaneous or mucosal
exposure to infected blood and various body fluids. Sexual transmission of hepatitis B may occur. In addition, infection can occur during medical,
surgical and dental procedures,
tattooing, or through the use of razors and similar objects are contaminated
with infected blood.
Risk factors
associated with HBV infection:
Surgical
side:
Major risk factors in
surgical patients include re-use of contaminated syringes, contaminated
surgical instruments and blood products. in orthopedic patients
common risk factors are previous history of surgery or blood transfusion .
Major risk factors for health care workers are dental procedures, needle prick
and surgical procedures. History of dialysis for more than 2 years
is a risk factor for dialysis patients.
Non surgical side:
Major risk factors
for mother to infant transmission include increasing maternal age, number of
pregnancies, repeated injections and addiction.It is established
fact that HBsAg does not cross the placental barrier however; the infection in
children/newborns may occur at the time of birth or soon after birth. The
infants of HBV positive mothers must be vaccinated soon after birth and HBIG
immediately within 24 hours of birth.
Prevention:
Preventive strategies
for HBV infection include healthy blood transfusion services along with safe
sex., The hepatitis B vaccine is the mainstay of hepatitis B
prevention the complete vaccine series induces protective antibody levels in
more than 95% of infants, children and young adults. Protection lasts at least
20 years and is probably lifelong.Better training of healthcare
workers.All patients needing surgery should be screened for viral hepatitis
and there should be separate operation theatres facilities for patients..
In addition reuse of razors in many barber shops that may spread hepatitis in a
substantial number of individuals. and must be discouraged.
Treatment:
There
is no specific treatment for acute hepatitis B. Therefore, care is
aimed at maintaining comfort and adequate nutritional balance, including
replacement of fluids lost from vomiting and diarrhoea. Early antiviral treatment
may be required in fever than 1% of people, whose infection takes a very
aggressive course (fulminant hepatitis) or who are immunocompromised.
On the other hand, treatment of chronic infection may be necessary to reduce the risk of cirrhosis and liver cancer.
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