Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.
Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
The term 'hepatitis' means inflammation of the liver. Hepatitis can be caused
by viruses, other
infectious agents, alcohol, and other chemicals. The two viruses that most
commonly infect the liver are the hepatitis A virus and the hepatitis B virus.
Although their names are similar, these viruses are not related. They differ in
the way they are transmitted from person to person and their ability to cause
chronic infection.
Hepatitis A
Hepatitis A is caused by a virus which is spread predominately through the
fecal-oral route when small amounts of infected fecal matter are inadvertently
ingested. Infected individuals shed large amounts of the virus in their stool,
starting about two weeks before symptoms present, and continue shedding the
virus in their stool for one to three
months.
Close contact with an infected person increases the chances of
contracting
the virus.
Children are particularly contagious because they have lower
standards of hygiene and may not appear sick.
The hepatitis A virus also may be
spread by ingestion of food or water that is contaminated by infected
individuals.
Much less commonly, contaminated needles or blood may spread
hepatitis A.
Some patients with hepatitis A infection have no symptoms, and
these asymptomatic infections
are more common in children.
Although the
symptoms resolve over several weeks, fatigue can be prolonged. Rarely, viral
hepatitis caused by hepatitis A can lead to liver failure, coma and death.
Hepatitis A does not cause chronic or persistent
infection of the liver. Once a person has recovered from hepatitis A, he or she
is immune to reinfection with
hepatitis A for life. This is true because effective antibodies are developed
against the hepatitis A virus. After infection with hepatitis A, these
antibodies provide life-long protection against the virus. The ability of the
body to make protective antibodies after infection with hepatitis A led
researchers to develop vaccines against the disease.
Hepatitis A vaccine is made of killed hepatitis A viruses and causes the
body's immune system to produce antibodies against the hepatitis A virus. In 94% to 100%
of vaccine recipients, antibodies start to develop immediately after the first
dose but do not reach protective levels for 2 to 4 weeks. A second dose of the
vaccine is recommended at least six months after the first dose to provide
prolonged protection.
Two hepatitis A vaccines are currently available in the
United States; these vaccines are
hepatitis a vaccine injection
(Havrix and Vaqta). The vaccine is given
as an injection into the deltoid muscle of the arm. Both Havrix and Vaqta
provide high level protection against hepatitis A. There is also a combination
vaccine called
hepatitis-b-hepatitis-a-vaccine injection (Twinrix) that protects against both hepatitis A and hepatitis B.
The dosing schedule for Twinrix is different from the other hepatitis A vaccines
and requires three doses over six months.
In the United States, hepatitis A
vaccination is recommended for all children
at one year of age. Vaccination also is recommended for individuals in high-risk
settings. Examples include:
Side effects of the hepatitis A vaccine usually are
mild. Soreness at the site of injection is common. Less commonly, recipients may
complain of headache
or fatigue. Serious allergic reactions are possible, but are rare.
A second option for protecting people against hepatitis A is to administer
antibodies that are already programmed to attack the virus. When people donate
blood, the part of the blood carrying antibodies (the 'immune globulin'
fraction) can be separated. Because some blood donors are likely to have
antibodies against the hepatitis A virus, pooled immune globulin from many
donors is likely to contain antibodies against hepatitis A. This immune globulin
can be injected into a person at risk for hepatitis A and will provide immediate
but temporary protection against infection. Protection with immune globulin
lasts two to four months depending on the dose. Immune globulin is used when
immediate protection against hepatitis A is required. An example would be
someone who is leaving immediately to travel to rural areas of a developing
country. Such a traveler would also receive hepatitis A vaccine but would not
have time to develop antibodies before departure. Immune globulin sometimes is
in short supply and should be used only when necessary.
If an unvaccinated person is exposed to hepatitis A, he or she should be
given the vaccine or immune globulin as soon as possible.
Vaccine is used for
exposed persons aged one to 40 years.
Immune globulin currently is recommended
for exposed persons over the age of 40 years.
These measures will reduce the
risk that the exposed person will contract hepatitis A by 85% to 90% if given
within two weeks of exposure.
Liver cancer is the fifth most common cancer in the world and the majority of patients with liver cancer will die within one year as a result. Patients with associated cirrhosis caused by chronic hepatitis B or C infections, alcohol, and hemochromatosis are at the greatest risk of developing liver cancer. Many patients with liver cancer do not develop symptoms until the advanced stages of the tumor which usually makes prognosis poor. The combination of an imaging study (ultrasound, CT, or MRI scans) and an elevated blood level of alpha-fetoprotein will most effectively diagnose liver cancer, while a liver biopsy can make a definitive diagnosis. Medical treatments, including chemotherapy, chemoembolization, ablation, and proton beam therapy, are not very effective. Surgical removal of the tumor or a liver transplant may be most effective in certain cases.
Cirrhosis of the liver refers to a disease in which normal liver cells are replaced by scar tissue caused by alcohol and viral hepatitis B and C. This disease leads to abnormalities in the liver's ability to handle toxins and blood flow, causing internal bleeding, kidney failure, mental confusion, coma, body fluid accumulation, and frequent infections. Symptoms include yellowing of the skin, itching, and fatigue.
Liver disease can be cause by a variety of things including infection (hepatitis), diseases such as gallstones, high cholesterol or triglycerides, blood flow obstruction to the liver, and toxins (medications and chemicals). Symptoms of liver disease depends upon the cause; however, common symptoms may include nausea, vomiting, upper right abdominal pain, and jaundice. Treatment depends upon the cause of the liver disease.
Sexually transmitted diseases, or STDs,
are infections that are transmitted during any type of sexual exposure,
including intercourse (vaginal or anal), oral sex, and the sharing of sexual
devices, such as vibrators. Women can contract all of the STDs, but may have no symptoms, or have different symptoms than men do.
Hepatitis C is an inflammation of the liver due to the hepatitis C virus (HCV), which is usually spread by
blood transfusion, hemodialysis, and needle sticks, especially with intravenous
drug abuse. Chronic hepatitis C may be treated with interferon, usually in combination with anti-virals.
The hepatitis B virus is a unique, coated DNA virus belonging to the Hepadnaviridae family of viruses. The course of the virus is determined primarily by the age at which the infection is acquired and the interaction between the virus and the body's immune system. Successful treatment is associated with a reduction in liver injury and fibrosis (scarring), a decreased likelihood of developing cirrhosis and its complications, including liver cancer, and a prolonged survival.
Sexually transmitted diseases, or STDs, are infections that are transmitted during any
type of sexual exposure, including intercourse (vaginal or anal), oral sex, and
the sharing of sexual devices, such as vibrators. Although treatment exists for many STDs, others currently are
usually incurable, such as those caused by HIV, HPV, hepatitis B and C, and HHV-8.
Hepatitis is most often viral, due to infection with one of the hepatitis viruses (A, B, C, D, E, F (not confirmed), and G) or another virus (such as those that cause infectious mononucleosis, cytomegalovirus disease). The main nonviral causes of hepatitis are alcohol and drugs. Many patients infected with hepatitis A, B, and C have few or no symptoms of illness. For those who do develop symptoms of viral hepatitis, the most common are flu- like symptoms including: loss of appetite, nausea, vomiting, fever, weakness, tiredness, and aching in the abdomen. Treatment of viral hepatitis is dependant on the type of hepatitis.
The liver is the largest solid organ in the body, and is actually an gland. The liver has a wide variety of critical functions such as manufacturing proteins and metabolizing fats and carbohydrates. The liver also eliminates harmful biochemical waste products from the body (alcohol, drugs, toxins). The liver secretes bile that aids in digestion. Examples of diseases of the liver include cirrhosis, hepatitis, cancer, and fatty liver. Symptoms of liver disease include bleeding, easy bruising, edema, fatigue, and jaundice.
Pregnancy planning is important to help prevent exposure of the mother and fetus to potentially harmful medications and substances during the early days, and throughout the pregnancy. Nutritional planning, prevention of birth defects, conditions such as high blood pressure, heart disease, diabetes, and kidney disease need careful monitoring. Gestational diabetes, preeclampsia, and pregnancy induced hypertension are conditions that may arise during pregnancy. Immunizations, inherited disorders, exercise, air travel, intercourse, and birth control are important factors to consider when planning a pregnancy.
Hepatitis means inflammation of the liver. Hepatitis A is one type of liver disease caused by a virus. Since hepatitis A is a virus, it can pass from person to person from eating or drinking contaminated food or coming into contact with contaminated materials containing the virus. Symptoms of hepatitis A include stomach pain, diarrhea, dark yellow urine, jaundice, and more. There is a vaccine to prevent contracting hepatitis A.
Travelers should prepare for their trip by visiting their physician to get the proper vaccinations and obtain the necessary medication if they have a medical condition or chronic disease. Diseases that travelers may pick up from contaminated water or food, insect or animal bites, or from other people include malaria, meningococcal meningitis, yellow fever, hepatitis A, typhoid fever, polio, and cholera.
When you are pregnant, many sexually transmitted diseases (STDs) can be especially harmful to you and your baby. These STDs include herpes, HIV/AIDS, genital warts (HPV), hepatitis B, chlamydia, syphilis, gonorrhea, and trichomoniasis. Symptoms include bumps, sores, warts, swelling, itching, or redness in the genital region. Treatment of STDs while pregnant depends on how far along you are in the pregnancy and the progression of the infection.
Early warning signs of job stress include headache, sleep disturbance, difficulty in concentrating, short temper, upset stomach, job dissatisfaction, and low morale. Stress on the job can be damaging to your health in that job stress is the outcome when job demands cannot be met.
The term 'hepatitis' simply means
inflammation of the liver. Hepatitis may be
caused by a virus or a toxin such as alcohol. Other viruses that can cause
injury to liver cells include the hepatitis A and
hepatitis C viruses. These
viruses are not related to each other or to hepatitis B virus and differ in
their structure, the ways they are spread among individuals, the severity of
symptoms they can cause, the way they are treated, and the outcome of the
infection.
What is the scope of the problem?
Hepatitis B is an infection of the liver caused by the
hepatitis B virus (HBV). It is estimated that 350 million individuals worldwide
are infected with the virus, which causes 620,000 deaths worldwide each year.
According to the Centers for Disease Control (CDC), approximately 46,000 new cases of hepatitis B
occurred in the United States in 2006.
In the United States, rates of new infection were highest
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