Hepatitis B: 300 Million Carriers and Growing
Cirrhosis of the liver is the scarring and death of liver tissue. Cirrhosis occurs as a result of alcohol, malnutrition, or hepatitis. When it happens, the liver doesn't function normally, fluid can build up in the abdomen, blood pressure can increase, and sometimes brain disorders can occur.
Alpha interferon is a naturally occurring protein secreted by cells in response to viral infections. It enhances the production of certain chemicals in the body that help to boost the immune response. It also inhibits viral replication in infected cells.
If an accidental exposure to hepatitis B occurs in a person who is not immune, an effective response is to treat that person with hepatitis B immunoglobulin antibodies from people who are already immune to infection with hepatitis B.
The following series of events is from a CDC Case Report:
An infant born at the hospital receives neither hepatitis B vaccine nor hepatitis B immunoglobulin. The infant develops hepatitis B at 3 months of age and dies less than 2 weeks after the onset of symptoms.
This tragedy is preventable and should never happen again.
Infection with hepatitis D occurs only in patients already infected with hepatitis B. Hepatitis D is spread mainly by contaminated needles and blood. The simultaneous infection with hepatitis B and hepatitis D produces more severe illness and higher rates of long-term liver failure than hepatitis B alone. The disease usually goes away on its own; and due to its codependence on hepatitis B, hepatitis D is effectively prevented via the hepatitis B vaccine.
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.
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.
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.