Hepatitis B
IDENTIFICATION
Hepatitis B is a liver disease that results from infection with the
Hepatitis B virus. It can range in severity from a mild illness lasting a
few weeks to a serious, lifelong illness. Hepatitis B is usually spread
when blood, semen, or another body fluid from a person infected with
the Hepatitis B virus enters the body of someone who is not infected.
Onset is usually insidious with anorexia, abdominal discomfort,
nausea, vomiting and jaundice.
Differentiation from hepatitis A is clinically difficult.
Chronic infections are mostly due to infections in infancy and
childhood.
STANDARD CASE DEFINITION
Suspect (History)
An acute illness typically including acute jaundice, dark urine,
anorexia, malaise, extreme fatigue and right upper quadrant
tenderness .
Confirmed (Laboratory Tests)
Serum positive for IgM anti-HBc or, hepatitis B surface antigen
(HbsAg).
INFECTIOUS AGENT
Hepatitis B is caused by the hepatitis B virus (HBV) which is a 42 nm
DNA virus composed of a 27 nm nucleocapsid core antigen (HBcAg)
surrounded by an outer coat containing the surface antigen (HBsAg).
OCCURRENCE
There is no seasonal variation. In developing countries, the
infection is widespread in children but is most common in young
adults in the West.
RESERVOIR
Man is the chief source of infection.
Mode of Transmission
Transmission may occur by the following routes:
Parenteral or Percutaneous
Through infected blood, blood products, syringes, transfusion
apparatus , and even razors and nail clippers.
HBV infection is thus more common in nurses, surgeons, drug addicts
and those receiving repeated transfusion, such as hemophiliacs,
coronary bypass patients and those on hemodialysis.
Vertical or Perinatal Spread
Mother to infant transmission can occur when the mother is a chronic
carrier or suffers from acute HBV infection during the last trimester of
pregnancy. The infection might occur during birth
More than 90 % of infants infected by their mothers become chronic
carriers as their immature immunological system is not able to clear
the virus.
Permucosal Spread
HBsAg found in all body secretions and excretions, only blood, saliva,
vaginal fluid and semen have been found to be infective.
Sexual partners of HBV infected persons stand the risk of contacting
the infection (homo as well as heterosexual partners).
Hepatitis B can be transmitted from child to child during play or from
an adult to child by contact of body fluids through minor cuts, sores,
abrasions .
Who is at risk for Hepatitis B?
Have sex with an infected person
Have multiple sex partners
Have a sexually transmitted disease
Inject drugs or share needles, syringes, or other drug equipment
Live with a person who has chronic Hepatitis B
Infants born to infected mothers
Exposed to blood on the job
Hemodialysis patients
Travel to countries with moderate to high rates of Hepatitis B
INCUBATION PERIOD
Varies from 45 to 180 days, average 60 to 90 days, may be rarely as
long as 6 to 9 months. It may take as short as two weeks for HBsAg
to appear in the blood.
SUSCEPTIBILITY AND RESISTANCE
There is general susceptibility to infection. Immunity conferred is
solid.
If the virus persists in blood for more than 6 months. These are
called chronic carriers. The carrier state usually lasts in these persons
indefinitely
PREVENTIVE MEASURES
The following steps are important:
Avoid spilling blood during collection, storage and transport. Avoid all
unnecessary injections, infusions. Always use disposable needles and
syringes for HBsAg positive patients. Wash thoroughly hands
contaminated with blood.
Blood donors and the staff of blood banks, hemodialysis units,
pathology laboratories and operation theatres should be screened for
HBsAg positivity every 3 to 6 months.
Blood transfusion should be given only when absolutely necessary.
Pooled plasma should be avoided. Patients needing multiple blood
transfusions should be immunized with vaccine if found to be
negative for anti-HBs (antibody to HBsAg).
Antenatal care should include routine screening for HBsAg to prevent
perinatal transmission to infants.
Passive immunization
by administration of immune serum
globulin (ISG) or hepatitis B immunoglobulin (HBIG). The latter
contains a high titer of anti-HBs compared to ISG. The indications are
as follows:
Household contacts, especially children, of patients with hepatitis
When blood transfusion is given to a patient 5 ml may be given
intramuscularly on the day of transfusion to prevent development of
post-transfusion hepatitis.
HBIG:
Its specific indication is in case of infants born to HBsAg and
HBcAg positive mothers, the dose being 0.5 ml IM at birth and
repeated at 2 and 6 months.
•
Active immunization:
Hepatitis B vaccine is the first vaccine
against a cancer (primary liver cancer).
This vaccine is available either as monovalent or in combination
(DPT-HepB, DPT-HepB+ Hib and HepB-Hib, etc.).
hepatitis B vaccine are prepared by using the HBsAg by DNA
recombinant technology and it contains only the outer coat (surface
antigen) of the virus. Route is intramuscular and the site being
anterolateral aspect of thigh in infants.
For immunocompetent adults vaccine is administered at 0, 1 and 6
months as an intramuscular injection in the deltoid
Hepatitis B vaccination is recommended for:
All infants, starting with the first dose of Hepatitis B vaccine at birth
All children and adolescents younger than 19 years of age who have
not been vaccinated
People whose sex partners have Hepatitis B
Sexually active persons.
Men who have sexual contact with other men
People who share needles, syringes, or other drug-injection
equipment
People who have close household contact with someone infected with
the Hepatitis B virus
Health care and public safety workers at risk for exposure to blood or
blood-contaminated body fluids on the job
People with end-stage renal disease, including predialysis,
hemodialysis, peritoneal dialysis, and home dialysis patients
Travelers to region with moderate or high rates of hepatitis B.
People with chronic liver disease.
People with HIV infection.
Anyone who wishes to be protected from Hepatitis B virus infection
Side Effects
Most common side effects are soreness at injection site, fatigue,
headache, irritability and fever higher than 37.7°C.
Efficacy
Complete vaccine series induces protective antibody levels in 95
percent infants.
Hepatitis C
IDENTIFICATION
Hepatitis C is a contagious liver disease that ranges in severity from
a mild illness lasting a few weeks to a serious, lifelong illness that
attacks the liver.
It results from infection with the Hepatitis C virus (HCV), which is
spread primarily through contact with the blood of an infected
person. Hepatitis C can be either “acute” or “chronic.”
Chronicity is common, occurring more frequently than with hepatitis
B in adults.
Acute Hepatitis C virus infection
is a short-term illness that
occurs within the first 6 months after someone is exposed to the
Hepatitis C virus. For most people, acute infection leads to chronic
infection.
Chronic Hepatitis C virus infection
is a long-term illness that
occurs when the Hepatitis C virus remains in a person’s body.
Hepatitis C virus infection can last a lifetime and lead to serious liver
problems, including cirrhosis (scarring of the liver) or liver cancer.
Diagnosis depends on the exclusion of hepatitis A, B and delta
viruses and other causes of liver injury. A serologic test for antibody
to the agent has been developed.
INFECTIOUS AGENT
The lipid-enveloped agent is between 30 and 50 nm in diameter, RNA
virus, probably a flavivirus.
Hepatitis C is parenterally transmitted . Hepatitis C is usually spread
when blood from a person infected with the Hepatitis C virus enters
the body of someone who is not infected.
Sharing needles, syringes, or other equipment to inject drugs
Needle stick injuries in health care settings
Being born to a mother who has Hepatitis C
INCUBATION PERIOD
Ranges from 2 weeks to 6 months; most commonly, within 6 to 9
weeks.
PERIOD OF COMMUNICABILITY
From one or more weeks before onset of the first symptoms through
the acute clinical course of the disease, and indefinitely in the chronic
carrier states.
Some people are at increased risk for Hepatitis C, including
Current injection drug users
Past injection drug users, including those who injected only one time
or many years ago
Recipients of donated blood, blood products, and organs
Hemodialysis patients or persons who spent many years on dialysis
for kidney failure
People who received body piercing or tattoos done with non-sterile
instruments
People with known exposures to the Hepatitis C virus, such as
Health care workers injured by needlesticks
Recipients of blood or organs from a donor who tested positive
for the Hepatitis C virus
HIV-infected persons
Children born to mothers infected with the Hepatitis C virus
METHODS OF CONTROL
interferon alfa is used to treat acute hepatitis C for 6 to 24 weeks.
Ribavirin may also be used if HCV RNA fails to clear after 3 months of
interferon alfa therapy.
Hepatitis D
IDENTIFICATION
Onset is usually abrupt, with signs and symptoms resembling those
of hepatitis B. Hepatitis may be severe and is always associated with
a coexistent hepatitis B virus infection.
Delta hepatitis may be self-limiting or it may progress to chronic
hepatitis. Hepatitis delta virus (HDV) and hepatitis B virus (HBV) may
coinfect, or delta virus infection may be superimposed upon the HBV
carrier state.
INFECTIOUS AGENT
HDV is a 35 to 37 nm virus-like particle consisting of a coat of HBsAg
and a unique internal antigen, delta antigen. HDV is unable to infect
a cell by itself and requires coinfection with HBV.
Occurrence
Worldwide, with marked variation in prevalence. Occurs epidemically
or endemically in populations at high risk of HBV infection.
MODE OF TRANSMISSION AND METHODS
OF CONTROL
Similar to that of HBV.
Hepatitis E
IDENTIFICATION
The epidemiology and clinical course are similar to that of hepatitis
A; there is no evidence of a chronic form. The case fatality rate is
similar to that of hepatitis A, except in pregnant women where the
rate may reach
20 percent during the third trimester of pregnancy.
Diagnosis depends on exclusion of other etiologies of hepatitis,
especially hepatitis A, by serologic means
INFECTIOUS AGENT
There is evidence that one virus or virus family is responsible for
hepatitis E. A 32-nm virus-like particle has been found in stools
during the early acute phase of infection .
RESERVOIR
Man, transmissible to chimpanzees.
MODE OF TRANSMISSION
Contaminated water. Also probably from person to person by the
fecal-oral route.
INCUBATION PERIOD
Fifteen to 64 days; mean incubation period has varied from 26 to 42
days in different epidemics.
PERIOD OF COMMUNICABILITY
Not known, but may be similar to hepatitis A.
METHODS OF CONTROL
Similar to hepatitis A.
Hepatitis G
This virus was discovered in January 1996. It is a
flavivirus that is percutaneously transmitted and
associated with chronic viremia that lasts for at least
10 years.
HGV has been detected among blood donors, injection drug users,
hemophiliacs, hemodialysis patients and with chronic hepatitis B or C
infection, but it does not cause important liver disease.