Hepatitis C
Latifa T.F. Yeung, M.D., FRCPC
Research Fellow, Division of Pediatric Gastroenterology and Nutrition
University of Toronto, The Hospital for Sick Children
Toronto, Canada
and
Eve A. Roberts, M.D., FRCPC
Professor of Pediatrics, Medicine, and Pharmacology
University of Toronto, The Hospital for Sick Children
Toronto, Canada
What is hepatitis C?
Hepatitis C is an infection of the liver caused by a virus called "hepatitis C virus"
(HCV), an RNA virus. Before this virus was identified (in 1989), many cases of hepatitis
C infection were simply termed "non-A non-B hepatitis" (NANBH).
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How does HCV cause disease?
HCV may damage liver cells directly, or liver cells may get damaged when the body's
immune system fights the virus. The immune system often has trouble eliminating
the virus because HCV is very sneaky; it constantly changes parts of its protein
structure (forming "quasi-species") so that the human immune system cannot fight
it effectively. By evading the immune system, HCV causes long-term (chronic) infection
of the liver with low-grade liver cell damage (chronic hepatitis).
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Who gets hepatitis C?
HCV is spread by infected blood and body fluids. Many cases of hepatitis C are likely
from transfusion of contaminated blood products. Intravenous drug use is an important
way by which one might acquire HCV infection. High-risk sexual behaviors may lead
to transmission of HCV. Vertical transmission of HCV from mother to child during
pregnancy or delivery also may occur.
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What happens to children with hepatitis C?
Compared to adults, children tend to have a shorter duration of infection. Thus,
their disease tends to be milder, and they usually feel fine. However, doctors worry
that in time children with hepatitis C infection will develop severe liver damage
and scarring. On the other hand, some children seem to have cleared their infection
without any treatment. There is still a lot to learn about how this disease affects
children.
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It turns out that my baby is not infected; what is "passive transfer of antibody"?
During pregnancy, mothers pass their antibodies to their babies. These antibodies
are meant to protect the baby until his/her own antibodies can develop. It is expected
that maternal antibodies of HCV disappear within the baby's first 18 months of life.
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How is hepatitis C diagnosed?
Most people find out they have hepatitis C after blood testing finds that they have
antibodies to the virus (anti-HCV), which shows that the immune system has been
exposed to the virus. At this point, further testing is done (see What will doctors
do for me if I have hepatitis C?).
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What will doctors do for me if I have hepatitis C?
Children with hepatitis C infection need to be monitored. Each time your child is
seen in a clinic, your child will be asked about how he/she is feeling and be examined.
Blood tests are helpful to see how your child's liver is doing. Blood testing also
can look for antibodies to the virus (anti-HCV), which reflect the body's exposure
to the virus. Testing for the actual virus (HCV RNA) also may be done.
Your doctor may suggest that a liver biopsy be performed; this procedure involves
taking a tiny sample of your child's liver so that it may be analyzed under the
microscope. The liver biopsy is the most direct way of seeing if there is significant
liver damage.
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Is there any treatment for hepatitis C?
Interferon-alpha is given by injection regularly for 6 to 12 months to try to cure
the infection. In adults, this drug works initially in some patients; however, many
patients relapse after the drug is stopped, and the hepatitis C infection comes
back. In most patients, treatment with interferon-alpha fails. This drug has side
effects that are similar to flu-like symptoms. Patients taking interferon-alpha
need to be monitored carefully.
Recently, it has been learned that two drugs are better than one. Ribavirin, combined
with interferon-alpha, appears to cure around 30% to 50% of adults with chronic
hepatitis C. Ribavirin is taken by mouth once or twice a day. It also needs to be
taken for a long time, usually for as long as the interferon-alpha is given. The
combination of ribavirin and interferon-alpha is being tested in children.
Decisions to treat HCV infection should be discussed with us. The currently available
treatments take a long time and demand a strong commitment. In addition, the success
rates are mediocre. Efforts are ongoing to find better combinations of drugs that
will be more effective at curing chronic hepatitis C.
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What are the complications of hepatitis C?
Although most people do not feel sick (i.e., they are asymptomatic), HCV causes
damage to the liver over a long period of time. Chronic hepatitis can lead to scarring
of the liver (cirrhosis) and eventually make the liver not function well. The scarring
of the liver also has been associated with a higher risk of liver cancer. In North
America, chronic hepatitis C is now the number one reason for liver transplantation
in adults.
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Can I spread HCV to people around me?
Exposure to blood contaminated with HCV is by far the most efficient means of spreading
HCV. In contrast, the spread of HCV from casual contact is very unlikely. Transmission
of HCV from sexual contact may occur, so precautions are necessary.
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Knowing that I have hepatitis C, is there anything I should do?
People with hepatitis C infection can get sicker than most people if they get an
additional form of hepatitis. Thus, people with chronic hepatitis C should receive
vaccination for hepatitis A and B.
Alcohol makes any liver disease worse. It makes chronic hepatitis C much worse.
Patients with hepatitis C infection are advised to abstain from alcohol (even "social
drinking").
Preventing spread of infection is an important public health issue. The sharing
of personal hygiene items, such as razors and toothbrushes, should be avoided. It
would be reasonable to beware of spreading HCV infection through sharing of other
objects that might have contaminated blood (e.g., needles used in ear or body piercing,
tattooing, or nail clippers). Teens who are sexually active should practice responsible
and safe sex.
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What is being done for prevention of hepatitis C?
Blood products are now screened for HCV by multiple effective methods. The risk
of getting hepatitis C from a blood transfusion is very low. Although there is ongoing
research to make a vaccine for HCV (which could protect people from getting infected),
this work faces such challenges as the HCV quasi-species problem; the constantly
changing virus makes it hard to perfect a vaccine.
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What research is being done?
Researchers are studying the virus to figure out how it infects cells and lives
in them. In doing so, better drugs can be made to kill the virus or to help boost
the patient's immune system to fight off HCV. To develop effective prevention and
treatment strategies for HCV infection, researchers must know what would happen
if the disease was allowed to play itself out, without any treatment. That is, researchers
are trying to work out the "natural history" of the chronic hepatitis C infection.
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Links to other information
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References
Cohen J. The scientific challenge of hepatitis C. Science 1999;285:26-30.
Alter MJ, Kruszon-Moran D, Nainan OV, et al. The prevalence of hepatitis
C virus infection in the United States, 1988 through 1994. New Engl J Med
1999;341:556-62.
Cerny A, Chisari FV. Pathogenesis of chronic hepatitis C: immunological features
of hepatic injury and viral persistence. Hepatology 1999;30:595-601.
Ahmed A, Keeffe E. Treatment strategies for chronic hepatitis C: update since the
1997 National Institutes of Health Consensus Development Conference. J Gastroenterol
Hepatol 1999;14 Suppl:S12-8.
Rosenthal E, Hazani A, Segal D, et al. Lack of transmission of hepatitis
C virus in very close family contacts of patients undergoing multitransfusions of
thalassemia. J Ped Gastro Nutr 1999;9:101-3.
About the Author
Dr. Yeung obtained her M.D. from the University of Toronto and completed her training
in pediatrics at the Hospital for Sick Children in Toronto, Canada. She is currently
a research fellow in the Division of Pediatric Gastroenterology and Nutrition at
the Hospital for Sick Children. Her research focuses on hepatitis C infection in
children.
Dr. Roberts obtained her M.D. from the Johns Hopkins University School of Medicine
and trained in hepatology at The Royal Free Hospital under Professor Dame Sheila
Sherlock. She is currently a professor of pediatrics, medicine, and pharmacology
at the University of Toronto and the Hospital for Sick Children.
Copyright 2012 Latifa T.F. Yeung, M.D., FRCPC, All Rights Reserved