Viral Hepatitis (cont.)
How is viral hepatitis prevented?
Prevention of hepatitis involves measures to avoid exposure to the viruses,
using immunoglobulin in the
event of exposure, and vaccines. Administration of immunoglobulin is called
passive protection because antibodies from patients who have had viral hepatitis
are given to the patient. Vaccination is called active
protection because killed viruses or noninfective components of viruses are
given to stimulate the body to produce its own antibodies.
Avoidance if exposure to viruses
Prevention of viral hepatitis, like any other illness, is preferable to reliance
upon treatment. Taking precautions to prevent exposure to another individual's
blood (exposure to dirty needles), semen (unprotected sex), and other bodily
waste (stool) will help prevent the spread of these viruses.
Use of immunoglobulins
Immune serum globulin (ISG) is human serum that contains antibodies to hepatitis
A. ISG
can be administered to prevent infection in individuals who have been exposed to
hepatitis A. ISG works immediately upon administration, and the duration of protection
is several months. ISG usually is given to travelers to regions of the world
where there are high rates of hepatitis A infection and to close or household contacts
of patients with hepatitis A. ISG is safe with few side effects.
Hepatitis B immune globulin or HBIG (BayHep B), is human serum that contains
antibodies to hepatitis B. HBIG is made from plasma (a blood product) that is known to
contain a high concentration of antibodies to the hepatitis B surface antigen. If given
within 10 days of exposure to the virus, HBIG almost always is successful in
preventing infection. Even if given a bit later, however, HBIG may lessen the
severity of HBV infection. The protection against hepatitis B lasts for about three
weeks after the HBIG is given. HBIG also is given at birth to infants born to
mothers known to have hepatitis B infection. In addition, HBIG is given to individuals
exposed to HBV because of sexual contact or to healthcare workers accidentally
stuck by a needle known to be contaminated with blood from an infected person.
Vaccination
Hepatitis A. Two hepatitis A vaccines are available in the US, Havrix and Vaqta.
Both contain inactive (killed) hepatitis A virus. For adults, two doses of the
vaccine are recommended. After the first dose, protective antibodies develop in
70% of vaccine recipients in 2 weeks and more than 95% of recipients in 4 weeks.
After two doses of the hepatitis A vaccine, immunity against hepatitis A
infection is believed to last for many years.
Individuals at increased risk for acquiring hepatitis A
and individuals with chronic liver disease (e.g., cirrhosis or chronic hepatitis C) should be
vaccinated. Although individuals with chronic liver disease are not at increased
risk for acquiring hepatitis A, they can develop serious (sometimes fatal) liver failure
if infected with hepatitis A and, thus, they should be vaccinated.
Individuals at increased risk of acquiring hepatitis A are:
- Travelers to countries where hepatitis A is common
- Men who have sex with men
- Illegal drug users (either injection or non-injection
drug use)
- Researchers working with hepatitis A or primates that are susceptible to
infection with hepatitis A
- Patients with clotting factor disorders who are receiving clotting factor
concentrates that can transmit hepatitis A
Some local health authorities or private companies may require hepatitis A
vaccination for food handlers.
Because protective antibodies take weeks to develop,
travelers to countries where hepatitis A is common should be vaccinated at least 4 weeks
before departure. The Centers for Disease Control (CDC) recommends immunoglobulin be given in addition
to vaccination if departure is prior to 4 weeks. Immunoglobulin provides quicker
protection than the vaccines, but the protection is short-lived.
Hepatitis B
For active vaccination, a harmless hepatitis B antigen is given to stimulate the body's
immune system to produce protective antibodies against the surface antigen of
hepatitis B. Vaccines that are currently available in the United States are made
(synthesized) using recombinant DNA technology (joining DNA segments). These recombinant
hepatitis B vaccines (Energix-B and Recombivax-HB) are
constructed to contain only that part of the surface antigen that is very potent
in stimulating the immune system to produce antibodies. The vaccine contains no
viral component other than the surface antigen and is not infectious. Hepatitis
B
vaccines should be given in three doses with the second dose 1-2 months after
the first dose, and the third dose 4-6 months after the first dose. For the best
results, the vaccinations should be given in the deltoid (shoulder) muscles and not in the
buttocks.
Hepatitis B vaccines are 95% effective. Five percent of vaccinated individuals will fail
to develop the necessary antibodies for immunity after the three doses. Patients
with weakened immunity (such as HIV infection), elderly
patients, and patients undergoing kidney hemodialysis are more likely to fail to respond to the
vaccines.
Hepatitis B vaccine is recommended for:
- All infants
- Adolescents under 18 years of age who did not receive
hepatitis B vaccine as infants
- People occupationally exposed to blood or body fluids
- Residents and staff of institutions for the
developmentally disabled
- Patients receiving kidney hemodialysis
- Hemophiliacs and other patients receiving clotting
factor concentrates
- Household contacts and sexual partners of patients
infected with hepatitis B chronically
- Travelers who will spend more than 6 months in
regions with high rates of hepatitis B infection
- Injection drug users and their sexual partners
- Men who have sex with men, men or women with multiple sex partners, or recent
infection with a sexually transmitted infection
- Inmates of long-term correctional facilities
All pregnant women should have a blood test for the
antibody to hepatitis B surface antigen. Women who test positive for hepatitis B risk
transmitting the virus to their infants during labor, and, therefore, infants born to mothers with
hepatitis B infection
should receive HBIG in addition to hepatitis B vaccine at birth. The reason for giving
both immunoglobulin and vaccine is that even though hepatitis B vaccine can offer long
lasting, active immunity, immunity takes weeks or months to develop. Until
active immunity develops, the short-lived, passive antibodies from the HBIG
protect the infant.
Unvaccinated individuals exposed to materials infected with hepatitis B (such as
healthcare workers stuck by a contaminated needle) will need HBIG in addition to
hepatitis B vaccine for the same reason as infants born to mothers with
hepatitis B infection.
Hepatitis C
There is currently no vaccine for hepatitis C.
- Many illnesses and conditions can cause inflammation
of the liver (hepatitis).
- Viruses that primarily attack the liver are called
hepatitis viruses. There are several types of hepatitis viruses including
types A, B, C, D, E, F (not yet confirmed), and G. Types A, B, and C are the
most common.
- Those at risk for viral hepatitis include workers in
the health care profession, people with multiple sexual partners, intravenous
drug abusers, and hemophiliacs. Blood transfusion is a rare cause of viral
hepatitis.
- All hepatitis viruses can cause acute hepatitis.
- Viral hepatitis types B and C can cause chronic
hepatitis.
- Symptoms of acute viral hepatitis include fatigue, flu-like symptoms, dark
urine, light-colored stools, fever, and jaundice. Rarely, acute viral hepatitis
causes fulminant hepatic failure.
- The symptoms of chronic viral hepatitis often are
mild and nonspecific, and the diagnosis of chronic hepatitis often is delayed.
- Chronic viral hepatitis often requires treatment in
order to prevent progressive liver damage, cirrhosis, liver failure, and liver
cancer
- Hepatitis infections can be prevented by avoiding exposure to viruses,
injectable immunoglobulins or vaccines.
Last Editorial Review: 2/29/2008
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