HEPATITIS B VIRUS
The risk of infection is directly correlated with the degree of contact with blood in the workplace and the status of the source person. The highest risk for infection is found in people exposed via a break in their skin to contaminated blood of a person who is positive for both Hepatitis B surface Antigen (HBsAG) and Hepatitis B e Antigen (HBeAG) - portions of the virus that are responsible for the disease. The HBV virus can be found in several body fluids, such as breast milk, bile, feces, saliva, semen and sweat. However, the highest HBV titers of all body fluids, and the most important, are found in blood.
Post Exposure Prophylaxis (PEP):
Antibodies are one part of a human's immunity. In general, humans who are exposed to foreign organisms (e.g., bacteria, viruses) will produce antibodies in order to fight those organisms and destroy them. Once antibodies are produced, the immune system can produce even more antibodies upon further exposure. In a sense, the immune system has a 'memory' of the foreign organism.
The idea of vaccination relies on the capacity of the immune system's "memory" of a foreign organism. A small dose of an organism, small enough so that actual disease is not achieved, will produce an immune response and the development of antibodies. After the organism is destroyed, the body will stop making antibodies to fight it, but it will still have a "memory" of that organism. Upon further exposure, even if at high doses, which could produce disease, the immune system will be able to produce enough antibodies to control the organism, destroy it, and thereby avoid disease.
Naturally, there are cases in which people never had a vaccination or an exposure to a specific organism. They are thus at a higher risk of developing disease, because their immune system may not be able to produce enough antibodies to fight the organism. However, there is a medical treatment in such situations. Medical centers have stores of collected, preformed antibodies that they can give patients who don't have antibodies themselves. These antibodies are also called immunoglobulins.
When the administration of Hepatitis B Immunoglobulin is indicated, it should be administered as soon as possible after exposure, ideally within 24 hours. In the occupational setting, multiple doses of Hepatitis B Immunoglobulin (antibodies to Hepatitis B) initiated within one week following percutaneous (through the skin) exposure to HBsAG-positive blood provides an estimated 75% protection from HBV infection. The Hepatitis B Vaccine should also be administered as soon as possible, and may be given at the same time as the immunoglobulins, but at a different site.
Vaccination against HBV
Over 100 million people in the US have been vaccinated as of 2000. In fact, OSHA stipulates that vaccinations must be offered to workers with risk for exposure. It is heartening to know that around 95% of all fire fighters are in fact vaccinated against HBV.
The Hepatitis B Vaccine is administered as a series of three injections, separated in time, into the deltoid muscle. 1 - 2 months after completing the series, a person may be tested for response by checking for anti-HBV antibodies. Non-responders to vaccination should be counseled about re-vaccination (they have a 30 - 50 % chance of responding to a second 3-dose series) and about any precautions they should take.
Any blood or body fluid exposure sustained by an unvaccinated, susceptible (non-immunized) person should lead to the initiation of the hepatitis B vaccine series.
(The above reflects information from: Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis Vol 50, No RR11;1 06/29/2001)