What is Hepatitis B?
Hepatitis B is a contagious liver infection caused by the hepatitis B virus (HBV). The natural course of hepatitis B disease is different from one person to another.
- The first phase of disease, during the first 6 months after a person becomes infected, is called acute hepatitis B infection. During this phase, many people show no symptoms at all. Among those who do have symptoms, the illness is usually mild and most people don't recognize that they have liver disease.
- In 90% of persons who become infected as adults with hepatitis B, the immune system successfully fights off the infection during the acute phase -- the virus is cleared from the body within 6 months, the liver heals completely, and the person becomes immune to hepatitis B infection for the rest of their life. In the other 10%, the immune system cannot clear the virus and hepatitis B infection persists past 6 months, usually for the rest of the person's life. This persistent state is known as chronic hepatitis B infection.
- When babies become infected at birth or during infancy, the percentages are reversed -- only 10% clear the infection. The remaining 90% develop chronic hepatitis B infection.
- In chronic hepatitis B infection, the liver becomes inflamed and scarred over a period of years. However, the speed at which inflammation and scarring take place varies between people. Some develop severe liver scarring (cirrhosis) within 20 years. In others, liver disease progresses slowly and does not become a major problem during their lifetime.
- Another concern is the potential for liver cancer. Hepatitis B infection is the single most important cause of hepatocellular (liver) cancer.
Treatment with anti-viral drugs works for some people with HBV who are starting to develop liver damage. Whether treatment will be successful depends on many factors, and these are best discussed with a physician who specializes in liver diseases. When treatment is successful, liver scarring and the potential for liver cancer are reduced.
How do people get the HBV Virus?
Hepatitis B virus is found in the blood of people with HBV infection. It enters the body through blood-to-blood contact.
Reliable blood tests for HBV were developed many years ago. Since blood donors and blood products are tested for HBV, this is no longer the typical means of infection.
In many parts of the world, hepatitis B virus infects more than 8% of the population. HBV-infected women pass the infection to their babies during the birth process. People can also get hepatitis B by sharing needles for injection drug use, through sexual contact with an infected person, by an accidental needlestick with a contaminated needle, or from improperly sterilized medical, acupuncture, piercing, or tattooing equipment.
Who is at Risk for Infection?
- Persons born in places where hepatitis B infection is common (especially China, Southeast Asia, the Pacific Islands, sub-Saharan Africa, and the Amazon basin in South America).
- Children of parents born in those places.
- Injecting drug users
- Hemodialysis patients
- Health care and public safety workers who may have contact with blood
- People having sex with an HBV-infected partner
- Men who have sex with men
- Those living in the same household with an HBV-infected person
- Travelers to places where hepatitis B infection is common who will have extended, close contact with the local population.
How is Hepatitis B Prevented?
Testing & Vaccination
- The hepatitis B vaccine offers excellent protection against HBV. The vaccine is safe and highly effective. Vaccination consists of 3 doses of vaccine (shots) over the course of 6 months. Protection lasts for 20 years to life.
- The American Academy of Pediatrics recommends that all children should receive hepatitis B vaccine starting at birth. (AAP Policy).
- The CDC recommends hepatitis B vaccine for persons traveling to countries where HBV is common (2008 Yellow Book).
- If you have one or more risk factors for hepatitis B infection, you should get a simple HBV blood test. The blood test will determine whether you are:
- immune to hepatitis B; or
- susceptible to hepatitis B and need vaccination; or
- infected with hepatitis B and need further evaluation by a physician
- The basic test for acute HBV infection is called the "Hepatitis B Core IgM Antibody test." People who have acute hepatitis B show positive IgM antibodies on this test.
- Find out where to get hepatitis B testing and vaccination in San Francisco
- California law requires testing of all pregnant women for hepatitis B infection
- If the mother is HBV-infected, she will pass the infection to the baby during the birth process, unless the baby gets immunized within hours of birth
- Giving the infant HBIG (hepatitis B immune globulin) and HBV vaccine right away will reliably prevent infection of the infant
- Other family members should best tested for hepatitis B too, and given vaccine if they are not already infected or immune
The best way to prevent hepatitis B is with vaccination. Other ways to reduce your risk of getting hepatitis B, hepatitis C, and HIV:
- Do not inject drugs. If you do inject drugs, stop and get into a treatment program. If you can't stop, never share needles, syringes, water, or "works"
- Do not share personal care items that might have blood on them (razors, toothbrushes)
- If you are a health care or public safety worker, follow universal blood/body fluid precautions and safely handle needles and other sharps
- Consider the risks if you are thinking about tattooing, body piercing, or acupuncture - are the instruments properly sterilized?
- If you're having sex with more than one steady partner, use latex condoms correctly and every time to prevent the spread of sexually transmitted diseases, including viral hepatitis and HIV.
After Exposure to Hepatitis B
- Hepatitis B infection can be prevented by getting vaccine and HBIG (hepatitis B immune globulin) soon after coming into contact with the virus.
- Persons who have recently been exposed to HBV should get HBIG and vaccine as soon as possible and preferably within 24 hours, but not more than 2 weeks after the exposure.
- If you have recently been exposed to hepatitis B, you should immediately contact your doctor or call the Communicable Disease Control Unit at (415) 554-2830.
What are the Symptoms of Hepatitis B?
After the virus enters the body, there is an incubation period lasting 1.5 to 6 months (average 4 months) until illness begins. During the acute phase (first 6 months after infection) most persons have no symptoms or might experience a mild illness. Symptoms of acute HBV infection, when present, may include:
- Jaundice (yellowing of the skin and eyes)
- Dark-colored urine, light-colored stools
- Abdominal pain
- Loss of appetite
During the chronic phase (> 6 months after infection) hepatitis B usually progresses silently, with no symptoms at all during the first 10-20 years. Signs of severe liver scarring (cirrhosis) may include:
- Ascites (accumulation of fluid and swelling of the abdominal cavity)
- Star-shaped vein pattern developing on the swollen belly
- Easy bruising and bleeding
Chronic HBV infection can lead to serious liver disease, liver scarring (cirrhosis), and hepatocellular (liver) cancer.
Because symptoms of hepatitis B are usually absent, persons with risk for HBV infection should be tested. If you think you have hepatitis B, or are at risk for hepatitis B, you should contact your doctor.