Hepatitis B is a serious public health problem that affects people of all ages in the United States and around the world. In 2001, an estimated 78,000 people contracted hepatitis B virus (HBV) infection in the United States. Hepatitis B is caused by a highly infectious virus that attacks the liver.
HBV infection can lead to severe illness, liver damage, and, in some cases, death. The best way to prevent hepatitis B is to be immunized with hepatitis B vaccine, a vaccine used in the U.S. since 1981 and proven safe and effective.
About 5% of people in the U.S. will get infected with hepatitis B sometime during their lives. If you engage in certain behaviors, your risk may be much higher. You may be at risk if you:
The largest outbreak of hepatitis B in the U.S. occurred in 1942 in military personnel who were given vaccine to protect them from yellow fever. It was unknown at the time that this vaccine contained a human blood component that was contaminated with hepatitis B virus. The outbreak caused over 50,000 cases of hepatitis B with jaundice.
Hepatitis A, B, and C are the names of different viruses that attack and injure the liver. All can cause similar symptoms.
Usually, people get hepatitis A from household or sexual contact with a person who has hepatitis A. Hepatitis A virus is spread from person to person by putting something in the mouth that has been contaminated with the stool of a person with hepatitis A. This type of transmission is called "fecal-oral." For this reason, the virus is more easily spread in areas where there are poor sanitary conditions or where good personal hygiene is not observed. Casual contact, as in the usual office, factory, or school setting, does not spread the virus.
Hepatitis C, formerly known as hepatitis non-A non-B, is caused by the hepatitis C virus and is spread in much the same way as hepatitis B. Both hepatitis B and C can cause lifelong liver problems, while hepatitis A does not. Vaccines to prevent hepatitis A and hepatitis B are now available. There is no vaccine yet for hepatitis C. If you've had hepatitis A or C in the past, it is still possible to get hepatitis B.
Hepatitis B is found in blood and certain body fluids—such as serum, semen, vaginal secretions—of people infected with hepatitis B virus. Hepatitis B is not found in sweat, tears, urine, or respiratory secretions. Contact with even small amounts of infected blood can cause infection. Hepatitis B virus can be spread by:
Hepatitis B virus IS NOT spread by:
Most people who get hepatitis B infection as babies or children don't look or feel sick at all. Similarly, almost half of adults who get infected don't have any symptoms or signs of the disease. If people do have signs or symptoms, they may experience any or all of the following:
Many people don't know when or how they acquired the infection. When they get the blood test results indicating they've been infected with hepatitis B, they are taken by surprise. Studies have demonstrated that 30% to 40% of people who acquire hepatitis B infection are unable to identify any risk factors explaining why they have the disease.
Nearly 95% of adults recover after several months. They clear the infection from their bodies and become immune. This means they won't get infected with hepatitis B again. They are no longer contagious and cannot pass hepatitis B on to others.
Unfortunately, of those who become newly infected with hepatitis B virus, about 5% of adults and up to 90% of children under age 5 are unable to clear the infection from their bodies. They become chronically infected and can pass the virus to others.
The only way to know if you are currently infected with hepatitis B, have recovered, are chronically infected, or are susceptible, is by having blood tests. The three standard blood tests are the following:
If the blood bank told you your test was "positive," it is important to find out which test was positive. If the "HBsAg" was positive, this means that you are either chronically infected with hepatitis B or were recently infected. If only the "anti-HBc" was positive, it is most likely that you either had a "false-positive" test or are immune to hepatitis B. It is important that you understand the full meaning of your test results. If you are not sure how to interpret these test results, call your blood bank for an explanation or have the blood bank send the test results to your physician. You may need to provide written permission for the blood bank to release these results to your physician. Your physician may want to repeat the blood tests or perform additional tests such as an "anti-HBs." Bring this information sheet along with you to your doctor visit. And remember, you cannot contract hepatitis B from donating blood, because the equipment used during blood donation is sterile.
People who do not recover from hepatitis B infection are chronically infected, and there are over 1 million chronically infected people in the United States today. A chronically infected person is someone who has had hepatitis B virus in her or his blood for more than 6 months.
About 5% of adults who acquire hepatitis B infection become chronically infected, but children younger than 5 years of age have a greater risk. The younger the child is at the time of infection, the greater the risk that the child will have a lifelong infection. Many babies born to chronically infected mothers will also become chronically infected with hepatitis B virus, unless the babies are given two shots in the hospital and at least two more during the 6 months after birth to protect them from the infection.
A chronically infected person usually has no signs or symptoms of hepatitis B infection, but remains infected for years or for a lifetime and can pass hepatitis B virus to others. Sometimes, chronically infected people will clear the infection from their bodies on their own, but most will not. Although most chronically infected people have no serious problems with hepatitis B and lead normal, healthy lives, some develop liver problems later. Chronically infected people are at much higher risk than the general population for liver failure or liver cancer.
A person with hepatitis B infection should see a physician knowledgeable about the management of liver disease every 6 to 12 months. The physician will do blood tests to check the health of the liver, as well as test for liver cancer. It is best for chronically infected people to avoid alcohol, because alcohol can injure the liver. Additionally, your physician should know about all the medicines you are taking, even over-the-counter drugs, because some medicines can hurt the liver. If there are any liver test abnormalities, consult a liver specialist regarding your need for further testing and treatment.
If your physician tells you your liver disease has progressed, here are some extra precautions you should take:
Each year, about 5,000 people in the U.S. die of hepatitis B-related liver failure. And another 1,500 people die from hepatitis B-related liver cancer.
Hepatitis B infection is the most common cause of liver cancer worldwide and ranks second only to cigarettes as the world's leading cause of cancer.