Viral hepatitis is an inflammation of the liver caused by infection with a virus. Two important types are hepatitis B and hepatitis C.

Hepatitis B

Hepatitis B (HBV) is typically transmitted through contact with contaminated body fluids, such as during sexual intercourse, sharing of contaminated drug needles or from exposure to open wounds, blood or secretions from an infected person. If a pregnant woman has hepatitis B, the baby can acquire the infection during birth.

Most infections with HBV are acute (last for a limited period of time). However, about 5 percent of infected adults develop chronic (long-lasting) infections. The American Liver Foundation estimates about 1.4 million Americans are currently infected with chronic HBV. Over time, chronic infection can lead to liver scarring (fibrosis) and cirrhosis (serious irreversible scarring). Some patients will eventually develop liver failure or liver cancer.

Hepatitis C

Hepatitis C (HCV) is transmitted through contact with contaminated blood. In the past, people could acquire the infection after receiving a transfusion of blood or blood product containing the virus. Now there's a test to screen blood for HCV. Currently, the most common methods of HCV transmission are through sharing of contaminated needles used for illicit drugs, acupuncture, tattooing or piercing. Healthcare workers may become infected if they are accidentally stuck with a contaminated needle or come into contact with contaminated blood.

The American Liver Foundation estimates about 4 million Americans have HCV. About 75 to 80 percent of those who are infected develop chronic infection. 20 percent of chronic infections lead to liver cirrhosis. Researchers say HCV is the leading reason for a liver transplant in the U.S. Each year, more than 10,000 Americans die from complications related to HCV infection.

Monitoring the Progression of Viral Hepatitis

Only a small number of patients with chronic hepatitis will develop liver cirrhosis, liver failure or liver cancer. But there is no way to predict which patients will progress. Many patients with liver damage don't have any signs until the disease has caused serious, irreversible damage. So doctors rely on liver biopsies to measure the amount of fibrosis, or scarring. Patients with more fibrosis may need more aggressive treatment to stem the damage to the liver.

In a liver biopsy, the doctor makes a small incision on the right side of the body, near the rib cage. A biopsy needle is inserted through the cut and into the liver. Then a small sample of the liver is removed. The tissue is sent to a lab for analysis. The lab technician can estimate the degree of liver damage by looking at the amount of scar tissue in the biopsy sample.

FibroScan® for the Liver

Researchers are testing a device, called FibroScan®, which uses ultrasound elastography to assess liver health. An ultrasound transducer with a vibrating unit is placed over the patient's abdomen. The vibrating transducer emits an elastic sound wave, then calculates the speed at which it passes through the liver. The velocity of the wave as it spreads is a measure of liver stiffness, or fibrosis. The faster the wave spreads, the stiffer, or harder the liver, which in turns means a greater amount of liver fibrosis.

Researchers are now confirming the efficacy of FibroScan's ability to measure the degree of liver fibrosis in patients with HBV and HCV. Patients who are scheduled for a liver biopsy will have the FibroScan followed by their regular biopsy. The results will be compared to track the diagnostic accuracy of FibroScan.

Bruce Bacon, M.D., a Gastroenterologist with St. Louis University School of Medicine, says although biopsies are typically only done every four to five years, they are an invasive procedure and can be painful. The FibroScan doesn't require any incisions or needles and can be repeated as necessary to follow a patient's progression. The study is also taking place in Boston, MA and Durham, NC. For more information log onto http://www.clinicaltrials.gov. Then type the trial identification number in the search box: NCT00125762.

For information about the clinical trial, log onto http://www.clinicaltrials.gov. Then type the trial identification number in the search box: NCT00125762.

For information about the FibroScan® technology:

http://www.echosens.com

For general information on hepatitis B or C:

American Liver Foundation

Centers for Disease Control and Prevention

HCV Advocate

Hepatitis Foundation International

National Institute of Diabetes and Digestive and Kidney Diseases