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 Hepatitis B Virus

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john



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PostSubject: Hepatitis B Virus   Wed Jun 08, 2011 7:46 am

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Hepatitis B Virus

Hepatitis B Overview


Hepatitis B Symptoms

What Are the Symptoms of Hepatitis B?

Half of all people infected with the hepatitis B virus have no symptoms.

Symptoms develop within 30-180 days of exposure to the virus. The
symptoms are often compared to flu. Most people think they have flu and
never think about having HBV infection.


  • Appetite loss
  • Feeling tired (fatigue)
  • Nausea and vomiting
  • Itching all over the body
  • Pain over the liver
    (on the right side of the abdomen, under the lower rib cage)
  • Jaundice - A
    condition in which the skin and the whites of the eyes turn yellow in color
  • Urine becomes dark in color (like cola or tea).
  • Stools are pale in color (grayish or clay colored).
Hepatitis B is an infectious hepatitis caused by the hepatitis B virus (HBV).
This infection has two possible phases; 1) acute and 2) chronic.

  1. Acute hepatitis B refers to newly acquired infections. Affected
    individuals notice
    symptoms approximately 1 to 4 months after exposure to the virus. In most people
    with acute hepatitis, symptoms resolve over weeks to months and they are cured
    of the infection. However, a small number of people develop a very severe,
    life-threatening form of acute hepatitis called fulminant hepatitis.
  2. Chronic hepatitis B is an infection with HBV that lasts longer than 6
    months. Once the infection becomes chronic, it may never go away completely.
Approximately 90% to 95% of infected adults are able to fight off the virus so
their infection is cured. Only about 5% to 10% of adults infected with HBV go on to
develop chronic infection. Children are at much higher risk for chronic
infection. Up to 90% of infected young children will fail to clear the virus from
their bodies and go on to develop chronic infection.
About two-thirds of people with chronic HBV infection are chronic carriers.
These people do not develop symptoms, even though they harbor the virus and can
transmit it to other people. The remaining one third develop "active" hepatitis,
a disease of the liver that can be very serious.

  • The liver is an important organ that filters toxins out of the blood,
    stores energy for later use, helps with digestion, and makes substances that
    fight infections and control bleeding.
  • The liver has an incredible ability to heal itself, but long-term
    inflammation caused by HBV can result in permanent damage.
  • Scarring of the liver is called cirrhosis, a condition traditionally
    associated with alcoholism but one that is also caused by chronic active
    hepatitis B infection. When this occurs, the liver can no longer carry out its
    normal functions and may fail completely. The only treatment for liver failure
    is liver transplant.
  • Chronic hepatitis B also can lead to a type of liver cancer known as
    hepatocellular carcinoma.
  • Any of these conditions can be fatal. About 15% to 25% percent of people with
    chronic hepatitis B die of liver disease.
Hepatitis B is the most common serious liver infection in the world.
Worldwide, about 350 million people are chronic carriers of HBV, of whom, more
than 620,000 die from liver-related disease each year.
In the United States, hepatitis B is largely a disease of young adults aged
20-50 years. About 800,000 to 1.4 million Americans are chronic hepatitis B
virus carriers, and
the disease causes about 3, 000 deaths each year.
The good news is that infection with HBV is usually preventable because
there is an effective vaccine. Use of the vaccine has resulted in an 82%
decrease in the number of new infections reported in the United States each
year.


Figure 1: Estimated and reported cases of hepatitis B in the United
States. Rates have fallen significantly since 1991 when routine
vaccination of children was started.
Image courtesy of the CDC.

Hepatitis B Transmission and Causes
The hepatitis B virus is known as a blood-borne virus because it is
transmitted from one person to another via blood or fluids contaminated with
blood. Another important route of transmission is from an infected mother to a
newborn child, which occurs during or shortly after birth.

  • Direct contract with blood may occur through the use of dirty needles
    during illicit drug use, inadvertent needle sticks experienced by healthcare
    workers, or contact with blood through other means. Semen, which contain small
    amounts of blood, and saliva that is contaminated with blood also carry the
    virus.
  • The virus may be transmitted when these fluids come in contact with broken
    skin or a mucous membrane (in the mouth, genital organs, or rectum) of an
    uninfected person
People who are at an increased risk of being infected with the hepatitis B
virus include the following:

  • Men or women who have multiple sex partners, especially if they don't use a
    condom
  • Men who have sex with men
  • Men or women who have sex with a person infected with hepatitis B virus
  • People with other sexually transmitted diseases
  • People who inject drugs with shared needles
  • People who receive transfusions of blood or blood products
  • People who undergo dialysis for kidney disease
  • Institutionalized mentally handicapped people and their attendants,
    caregivers, and
    family members
  • Health care workers who are stuck with needles or other sharp instruments
    contaminated with infected blood
  • Infants born to infected mothersIn some cases, the source of transmission is never known.
You cannot get hepatitis B from the following activities:
Having someone sneeze or cough on you

  • Hugging someone
  • Handshaking a persons hand
  • Breastfeeding your
    child
  • Eating food or drinking water
  • Casual contact (such as an office or social setting)
Hepatitis B Symptoms
Half of all people infected with the hepatitis B virus have no symptoms and
may never realize that they have been infected. Adults are more likely to develop
symptoms than children. For those who do get sick, symptoms usually develop within 1 to 4 months
after exposure to the virus. The initial symptoms are often similar to the flu.
Common symptoms of hepatitis B include:

  • Appetite loss
  • Feeling tired (fatigue)

  • Nausea and vomiting
  • Itching all over the body
  • Pain over the location of the liver (on the right side of the abdomen, under
    the lower rib cage)
  • Jaundice (a
    condition in which the skin and the whites of the eyes turn yellow in color)

  • Dark urine (the color of cola or tea)
  • Pale-colored stools
    (grayish or clay colored)

Many types of acute viral hepatitis
such as hepatitis A and
hepatitis C have symptoms
that are indistinguishable from hepatitis B.

Fulminate hepatitis is a severe form of acute hepatitis that can be
life-threatening if not treated right away. Fortunately, fulminate
hepatitis is rare. The symptoms
of fulminate hepatitis develop very suddenly and may include:

  • Mental disturbances such as confusion, lethargy, extreme sleepiness or hallucinations (hepatic encephalopathy)

  • Sudden collapse with fatigue
  • Jaundice
  • Swelling of the abdomen

Prolonged nausea and vomiting can cause
dehydration.
Individuals with dehydration may notice these symptoms:

  • Extreme weakness
  • Confusion or trouble concentrating
  • Headache
  • Lack of urination
  • Irritability
Symptoms of liver damage may include the following:

  • Fluid retention causing swelling of the belly (ascites) and sometimes the legs
  • Weight gain due to ascites
  • Persistent jaundice
  • Loss of appetite, weight loss,
    wasting
  • Vomiting with blood in the vomit
  • Bleeding from the nose, mouth, or rectum; or blood
    in the stool
  • Hepatic encephalopathy (excessive sleepiness, mental confusion, and in advanced stages, development of
    coma)


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When to Seek Medical Care

Call your health care professional if you have any of the following:

  • Nausea and vomiting that does not go away in 1-2 days
  • The inability to keep down liquids
  • A high fever or
    fever that persists more than 2 days
  • Yellow skin or eyes
  • Dark-colored urine (like tea or cola)
  • Pain in the abdomen.
For severe symptoms including confusion or delirium go to a hospital
emergency department.
You should also contact your health care practitioner if you think you may have
been exposed to the hepatitis B virus.
If you have chronic hepatitis B infection and think you might be pregnant; or
if you are pregnant and think you have been exposed to hepatitis B inform
health care practitioner right away.
Hepatitis B Diagnosis

Hepatitis B infection is diagnosed with blood tests. These tests can detect
pieces of the virus in the blood (antigens), antibodies against the virus, and
viral DNA ('viral load'). Blood tests for HBV are often done when routine blood
work shows abnormal liver function tests or in patients who are at an increased
risk for exposure. If a patient has had a large amount of vomiting or has not been
able to take in liquids, blood electrolytes may also be checked to ensure
that the patient's blood chemistry is in balance.
Other tests may be ordered to rule out other medical conditions.
X-rays and other diagnostic images are needed only in very unusual
circumstances.
If a patient is diagnosed with chronic hepatitis B, they will need regular
visits to their health care practitioner. Blood tests can help determine how active
the infection is and whether there has been damage to the liver.
Blood tests alone may not be enough to guide treatment in chronic HBV. Other
tests include:

  • CT scan or ultrasound: These diagnostic imaging tests are used to detect
    the extent of liver damage and may also detect cancer of the liver caused by
    chronic hepatitis B.
  • Liver biopsy: This involves removal of a tiny piece of the liver. It is
    usually done by inserting a long needle into the liver and withdrawing the
    tissue. The tissue is examined under a microscope to detect changes in the
    liver. A biopsy may be done to detect the extent of liver damage or to evaluate
    how well a treatment is working.
  • Hepatitis B Treatment

    Acute hepatitis B usually resolves on its own and does not require
    medical treatment. If very severe, symptoms such as vomiting or diarrhea

    are present, the affected person may require treatment to restore fluids
    and electrolytes. There are no medications that can prevent acute
    hepatitis B from becoming chronic. If
    a person has chronic hepatitis B, they should see their health care provider regularly.
  • Self-Care at Home
    The goals of self-care are to relieve symptoms and prevent worsening of the disease.
  • Drink plenty of fluids to prevent dehydration. Although, broth, sports
    drinks, gelatin, frozen ice treats (such as Popsicles), and fruit juices may
    be better because they also provide calories.
  • Ask your physician before taking any medications, even those that are
    over-the-counter. Some medications depend on the liver, and liver damage may
    impair the body's ability to metabolize these drugs. If you are on
    prescription medications, check with your physician to see if the doses
    should be adjusted or if the medication should be temporarily discontinued.
  • Avoid drinking alcohol until your health care practitioner allows it.
    Individuals
    with chronic HBV should avoid alcohol for the rest of their lives.
  • Try to eat a diet that provides adequate nutrition. Take it easy. It
    may take some time for your energy level to return to normal.
  • Avoid prolonged, vigorous exercise until symptoms start to improve.
  • Call your health care practitioner for advice if your condition worsens or
    new symptoms appear.
  • Avoid any activity that may spread the infection to other people (sexual
    intercourse, sharing needles, etc).
  • Medical Treatment
    Acute hepatitis B infection


    Acute hepatitis B infection is not treated with antiviral medications.
  • If the infected person is dehydrated from vomiting or diarrhea, a doctor may
    prescribe IV fluids to help them feel better. Medications may also be used to
    control these symptoms.
  • People with mild symptoms can be cared for at home.
Chronic hepatitis B infection
The degree of liver damage is related to the amount of active,
replicating (multiplying) virus in the blood and liver. Regularly
measuring the amount of HBV DNA ('viral load') in the blood gives your
physician a good idea of how fast
the virus is multiplying. The treatments now in use are classified as antiviral
drugs, because they try to stop the virus from multiplying.

  • Antiviral agents, while the best therapy known for chronic hepatitis B, do
    not work in all individuals with the disease.
  • There are several antiviral agents for chronic hepatitis B approved by the
    U.S. Food and Drug Administration (FDA). New drugs are always being tested and
    treatment recommendations are subject to change.
  • Antiviral therapy is not appropriate for everyone with chronic HBV infection.
    It is reserved for people whose infection is most likely to progress to active
    hepatitis or cirrhosis.
  • Decisions to start medications for treatment of hepatitis B are made by the
    patient and health care practitioner, often in consultation with a specialist in
    diseases of the digestive system (gastroenterologist) or liver (hepatologist).
  • The decision to treat is guided by results of liver function tests, HBV DNA
    tests, and, frequently, liver biopsies after a complete history and physical
    examination.
Treatment is usually started when blood tests indicate that liver functions
are deteriorating and the amount of replicating HBV is rising. Many people never
reach this point. For those who do, the interval between diagnosis and starting
treatment is quite variable.

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Hepatitis B Medications

All of the following medications described that are used to treat chronic
hepatitis B are antiviral medications. They reduce the ability of the virus to
reproduce in the body and give the liver a chance to heal itself. These drugs
are not a cure for hepatitis B, but they do reduce the damage caused by the
virus. Although these medications are similar in some ways, they differ in other
important ways. Talk to your health care practitioner about the best medication for
you.
Pegylated interferon alfa-2b (Pegasys®)
Pegylated interferon is used alone
or in combination with other medications.

  • Pegylated interferon slows the replication of the virus and boosts the
    body's immune system to fight the infection.
  • It works best in people who have relatively low levels of HBV DNA (low
    viral load).
  • Pegylated interferon usually is not given to people whose liver damage has
    progressed to cirrhosis, because it can make the liver damage worse.
  • Treatment is often given for 48 weeks, which is shorter than for other
    medications, but pegylated interferon requires regular shots (injections) while
    other medications are taken orally.
  • Pegylated interferon has unpleasant side effects in many people. The side
    effects are similar to having the
    flu. For many people, side effects are so
    severe that they cannot continue taking the medication.
  • Liver function tests and HBV DNA tests are used to check how well the
    treatment is working.
  • Interferon appears to stop the liver damage in up to 40% of people although
    relapse is possible.
Nucleoside/nucleotide analogues (NAs)
Nucleoside/nucleotide analogues (NAs) are compounds that mimic normal
building blocks for DNA. When the virus tries to use the analogues, it is unable
to make new viral particles. Examples of these agents include adefovir
(Hepsera®), entecavir (Baraclude®), lamivudine (Epivir-HBV®, Heptovir®,
Heptodin®), Telbivudine (Tyzeka®) and tenofovir (Viread®).

  • NAs reduce the amount of virus in the body. Between 20% and 90% of patients
    may have levels reduced so far that they become undetectable. Obviously, this is
    a broad range. The higher success rates are achieved in patients who do not have
    "hepatitis B e antigen" (HBeAg). HBeAg is detected by a blood test and indicates
    that the virus is actively multiplying.
  • Side effects are less common than with pegylated interferon. NAs have been
    associated with changes in body fat distribution, reduced blood cell counts, and
    increased levels of lactic acid in the blood. Rarely, NAs are associated with a
    severe flare of hepatitis that can be serious or fatal.
  • HBV may become resistant to NAs over time.
  • NAs do not cure the infection. Relapse is possible even in patients who
    have had a good response to treatment.
  • Surgery

    There is no surgical therapy for hepatitis B.
    If liver damage is so severe that the liver starts to fail,
    liver transplant may be
    recommended.
  • Liver transplant is a major process and surgery with an extended recovery period.
  • It also depends on the availability of a matching donor liver.
  • If liver transplant becomes a possibility for an individual, a health care
    practitioner will discuss the risks and benefits with them.
  • Hepatitis B Other Therapy

    No herbs, supplements, or other alternative therapy is known to work
    as well as antiviral medication in slowing HBV replication and promoting
    liver healing in hepatitis B. At this time, no specific herb or herbal
    preparation is recommended.
  • Hepatitis B Vaccine
    There is a vaccine against the hepatitis B virus (Engerix-B, Recombivax HB).
    It is safe and works well to prevent the disease. A total of 3 doses of
    the vaccine are given over several months. Hepatitis B vaccine is also
    produced as a combination product which includes other
    common childhood vaccinations. This can reduce the number of shots that a child needs at a single visit.
    The following groups should be vaccinated for hepatitis B:
  • All children younger than 19 years, including all newborns - especially those born to mothers who are infected with HBV
  • All health care and public safety workers who may be exposed to blood
  • People who have hemophilia or other blood clotting disorders and receive transfusions of human clotting factors
  • People who have end-stage renal disease including those who require hemodialysis for kidney disease
  • Travelers to countries where HBV infection is common. This includes most areas of Africa, Southeast Asia, China and
    Central Asia, Eastern Europe, the Middle East, the Pacific Islands, and the Amazon River basin of South America.
  • People who are in prison
  • People who live or work in residential facilities for developmentally disabled persons
  • People who inject illegal drugs

  • People with chronic liver disease such as hepatitis C
  • People who have multiple sex partners or have ever
    had a sexually transmitted disease
  • Men who have sex with men
  • Persons with HIV
  • People who have a sexual partner who is an HBV carrier.
  • Household contacts of persons who are carriers of HBV.
  • Anyone who wants to be vaccinated, regardless of risk factors
Hepatitis B immune globulin (BayHep B, Nabi-HB) is given along with the hepatitis B vaccine to unvaccinated people who have been exposed to hepatitis B.

  • These include close contacts of people with HBV infection, health
    care workers who are exposed to HBV-contaminated blood, and infants born
    to mothers infected with HBV.
  • Giving the immune globulin and the vaccine together in these situations prevents transmission of the disease in 80%
    to 90% percent of cases.
  • Follow-up

    If an individual has acute hepatitis B, a health care practitioner
    will draw blood and examine
    the person periodically to see if the infection is resolving. If the
    person develops chronic hepatitis B,
    they will need periodic examinations and blood tests on an ongoing
    basis. If these tests indicate that the virus is actively damaging the
    liver,
    the health care practitioner may suggest a liver biopsy or begin
    antiviral therapy.
    The individual will also be given a vaccine against hepatitis A, which is an unrelated virus that may cause severe liver disease in people who already carry hepatitis B.Chronic hepatitis B is associated with hepatocellular carcinoma.
    Fortunately, this is a rare cancer. A blood test can be used to detect a
    marker for this cancer or the cancer can be detected by abdominal
    ultrasound. Persons with chronic hepatitis B are usually screened
    periodically (every 6 to 12 months) for hepatocellular carcinoma,
    although it is not clear if this screening improves survival.
  • Hepatitis B Prevention
    In addition to the hepatitis B vaccine, other ways to protect yourself from HBV infection
    include:
  • If you are sexually active, practice safe sex.
    Correct use of latex condoms
    can help prevent transmission of HBV, but even when used correctly,
    condoms are not 100% effective at preventing transmission. Men who have
    sex with men should be vaccinated against both hepatitis A and hepatitis
    B.
  • If you inject drugs, don't share needles or other equipment.
  • Don't share anything (including grooming products) that might have blood on it, such as a razor, toothbrush,
    fingernail clippers, etc.
  • Think about the health risks if you are planning to get a tattoo or body piercing. You can become infected if the artist or
    person piercing you does not sterilize needles and equipment, use disposable gloves, or wash hands properly.
  • Health care workers should follow standard precautions and handle needles and sharps safely.
  • If you are pregnant or think you might be pregnant, tell your health care
    practitioner if you have any of the risk factors for HBV infection.

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PostSubject: Re: Hepatitis B Virus   Wed Jun 08, 2011 7:55 am

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Hepatitis B Prognosis

Some people rapidly improve after acute hepatitis B. Others have a more prolonged disease course with very slow improvement
over several months, or with periods of improvement followed by worsening of symptoms. A small group of people (about 1% of
infected people) suffer rapid progression of their illness during the acute stage and develop severe liver damage (fulminate
hepatitis). This may occur over days to weeks and may be fatal.Other
complications of HBV include development of a chronic HBV infection.
People with chronic HBV infection are at further risk for liver damage
(cirrhosis), liver cancer, liver failure, and death.Hepatitis B Resources
and Information

American Liver Foundation
www.liverfoundation.org
(800) 465-4837 Hepatitis B Foundation
www.hepb.org
(215) 489-4900 Hepatitis Foundation International
www.hepatitisfoundation.org
(800) 891-0707
Synonyms and Keywords
cirrhosis, fulminant hepatitis, hepatitis B virus, HBV, hepatocellular carcinoma,
liver cancer, liver failure, liver transplant, yellow jaundice,
hepatitis A, hepatitis B, acute hepatitis B, chronic hepatitis B, HBV
infection, hepatitis B infection, hepatitis B causes, hepatitis B
symptoms, hepatitis B treatment, liver biopsy, antiviral medications,
hepatitis B vaccine, immune globulinAuthor: Mary D. Nettleman, MD, MS, MACP. Professor and Chair.
Department of Medicine, College of Human Medicine, Michigan State
University
Editor: Bhupinder Anand, MD, Professor, Department of Internal
Medicine, Division of Gastroenterology, Baylor University College of
Medicine

REFERENCES:

Centers for Disease Prevention and Control. Disease Burden from Viral Hepatitis A, B, and C in the United States.

Previous contributing authors and editors: Author: Sandeep Mukherjee,
MD, MB, BCh, Assistant Professor, Department of Internal Medicine, Section of
Gastroenterology and Hepatology, University of Nebraska Medical Center.

Editors: Simmy Bank, MD, MB,
ChB, Chair, Professor, Department of Internal Medicine, Division of
Gastroenterology, Long Island Jewish Hospital, Albert Einstein College of
Medicine; Mary L Windle, Pharm D, Adjunct Assistant Professor, University of
Nebraska Medical Center College of Pharmacy; Pharmacy Editor, eMedicine.com, Inc

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