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).
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).
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.
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.
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.
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?).
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.
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.
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.
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.
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.
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.
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.
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
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