Viral Hepatitis: Hepatitis B: 300 Million Carriers and Growing

Hepatitis B: 300 Million Carriers and Growing

Hepatitis B is highly prevalent in the United States, with approximately 1.2 million chronic carriers. Hepatitis B is the ninth leading cause of death worldwide, and there are more than 300 million carriers. Hepatitis B may develop into a chronic disease in up to 10 percent of newly-infected people each year. If left untreated, the risk of developing cirrhosis (scarring) and liver cancer becomes higher.

How You Get It

Hepatitis B is highly infectious and is transmitted through infected blood and other body fluids (seminal fluid, vaginal secretions, breast milk, tears, saliva, and open sores). Like many other sexually transmitted diseases, hepatitis B is spread through unsafe sexual practices. Health-care workers, prison personnel and inmates, and intravenous drug users are at particularly high risk.

The blood supply in the United States has been screened for hepatitis B for many years, and transfusion-related illness is extremely rare; however, recipients of blood or blood products before 1975, when screening started, are at risk. Hepatitis B is transmitted from mother to infant in the last few months of pregnancy, which is a major mode of transmission in regions where the disease is endemic.

What It Feels Like

Most people who get hepatitis B have no recognizable signs or symptoms. When they do appear, symptoms include flu-like illness, loss of appetite, nausea and vomiting, fever, weakness, and mild abdominal pain. Dark urine and jaundice may also be observed. Most adults (90 to 95 percent) recover within six months, while 5 to 10 percent develop chronic hepatitis or become carriers. About 50 percent of infected young children will become chronically infected.

Chronic infection can result in cirrhosis, liver failure, and death in severe cases. Liver cancer is also associated with hepatitis B. Hepatitis B carriers are potentially infectious even though they have no symptoms.

Chronic infection comes in two forms. In the first, the virus multiplies rapidly and is easily detected. In the second, there are low rates of viral replication and it is difficult to detect. Patients with the first form of the disease generally have a worse prognosis and a greater chance of developing cirrhosis and cancer.

Detecting B

Both blood and molecular tests are useful in the diagnosis of viral hepatitis. They may detect early infections before other signs of disease appear, and can distinguish between acute and chronic infections.

Nearly all infected individuals will have detectable hepatitis B antigens. Acute infection is diagnosed by the presence of both antigens and antibodies; the antibody develops in the early stages of infection, at the time symptoms appear (the same antibodies are also produced by vaccination). Most people with acute infection retain some antibodies, but in some cases, the antibody response wanes over time. This makes it difficult to diagnose reinfection. Diagnosis of hepatitis B should be confirmed by a liver biopsy.

Hepatitis B-Associated Cancer

Hepatocellular carcinoma (HCC), a form of liver cancer, is the most common malignant tumor found in males worldwide, with one million new cases each year, mostly in Southeast Asia and Sub-Saharan Africa. The incidence of this cancer is closely associated with hepatitis B infection in endemic regions. Chronic alcohol consumption and cirrhosis, along with chronic viral infection, increase the development of cancer. Cancer screening should include an ultrasound examination.

Treating B

Although there is no treatment for acute hepatitis B, there are two approved treatments for chronic hepatitis B, the first being alpha interferon. The exact way that alpha interferon works is unknown, but it is thought to restrict viral replication and attachment and boost T cells. Unfortunately, people with a weakened immune system do not respond well to therapy. Alpha interferon therapy often results in a number of side effects, including flu-like symptoms, fatigue, headache, nausea and vomiting, loss of appetite, depression, and hair thinning. Because interferon may depress the bone marrow, blood tests are needed to monitor white blood cells and platelets.

The second treatment, a drug named Lamivudine, stops viral replication. Drug resistance can occur, but usually after 9 to 12 months of exposure and at a rate of only 10 to 15 percent per year. A once-a-day tablet, Lamivudine is less expensive and has fewer severe side effects than alpha interferon. The most common side effectsare fatigue, headache, nausea, and abdominal pain. Neither therapy is considered great because of the side effects, but they are currently the only two available.

There Is a Vaccination, But It's Expensive

All individuals at risk for infection should be vaccinated, as well as all children and adolescents, because most cases occur in sexually active young adults. Chronic infection remains a major problem worldwide, despite some declines due to the hepatitis B vaccine. Patients with chronic hepatitis B should also be vaccinated against hepatitis A.

Excerpted from The Complete Idiot's Guide to Dangerous Diseases and Epidemics © 2002 by David Perlin, Ph.D., and Ann Cohen. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.