血液供给的安全性
BALTIMORE (Johns Hopkins Health Insider) - Last summer, the Food and Drug Administration (FDA) restricted blood donations from people who had visited Britain for six months or longer between 1980 and 1996. The reason for this alarming measure? To prevent contamination of the blood supply by an infectious agent believed to be related to bovine spongiform encephalopathy, or mad cow disease, which had been epidemic in British cattle during those years.
Fears about the blood supply are unwarranted. To date, no cases of mad cow disease have been reported in the United States. Nor has it been shown to be transmissible to humans via blood. But government officials are taking no chances. By restricting donations from frequent travelers to Britain, they have virtually eliminated the remote possibility of transfusion-related mad cow disease. That precaution is just the latest example of the ongoing improvements that make the blood supply in the United States safer than it has ever been.
, 百拇医药
Safety Guarantees
The blood supply is protected by a series of checks, tests and re-tests. The primary level of safety starts with the donor. Blood donation in the United States is voluntary and without pay. That‘s because when blood is given in exchange for money or for reasons other than altruism, the chances increase that people with a blood-borne disease might conceal their illness to reap the rewards.
Before they donate, all volunteers are asked for an extensive medical history to reveal potential exposure to disease risks. The history includes questions about foreign travel, high-risk sexual activity and intravenous drug use. The screening process is conservative to exclude anyone who might have been exposed to a blood-borne disease. For example, people who have traveled recently to an area where malaria is common will be temporarily excluded, even if they show no signs of the disease.
, 百拇医药
After giving blood, donors have an additional chance to exclude themselves by confidentially requesting that their blood not be used. That allows participation at times when donating blood seems obligatory, such as at a workplace drive or when a family member is ill. If a high-risk donor feels it would be socially awkward not to donate, he or she can go through the process and still have the blood discarded secretly afterward.
The next level of safety involves the quality of the blood itself. Every unit is put through a battery of tests to check for hepatitis B, hepatitis C, HIV (the virus that causes AIDS), HTLV-1 (a retrovirus similar to HIV) and syphilis. There are actually three tests for HIV, which allow us to identify carriers more accurately and quicker. With the current combination of tests, anyone infected with HIV would test positive within approximately 10 days of infection, as opposed to the six months that had been standard. And because most blood donors give repeatedly, their blood is tested often, further reducing the chance that a disease will slip through.
, 百拇医药
Despite those testing and safety measures, the system is not foolproof. There‘s still a risk - albeit extremely slight - of developing a transfusion-related disease. For example, the risk of acquiring HIV from a transfusion is way down, somewhere from one in 500,000 to one in 1 million per unit of blood. These numbers are considerably lower than in 1987, when the American Red Cross estimated a risk of about one in 150,000. Some rare diseases, such as malaria, may slip through simply because we are unable to test for them.
, 百拇医药
Reducing the Risk
In an emergency, donated blood may save your life. That‘s a powerful benefit to trade off against a pretty slim risk. Moreover, if you‘re facing elective surgery, you can reduce the risk of transfusion-related disease to the vanishing point by donating blood to yourself.
In the future, other risk-reducing options may become available. Researchers are investigating recombinant technology as a way of creating pharmacologic treatments that may be just as effective as human blood components. Scientists are also working on ways to sterilize platelets and red blood cells with techniques similar to those currently being used to sterilize blood plasma. That would yield blood transfusions that had been cleared of all viral activity and bacteria.
, http://www.100md.com
Another step you can take if you‘re facing surgery is to find out whether your hospital is accredited by the American Association of Blood Banks. All hospitals and blood banks are inspected by the FDA, but the AABB also conducts a voluntary inspection and offers certification to topnotch facilities. Nearly all blood centers and about two-thirds of hospitals belong to the association. Call the blood bank at your hospital and ask if it‘s accredited by the AABB. If it‘s not, discuss your safety concerns with your surgeon, and ask if there‘s an accredited hospital you can use instead., http://www.100md.com
Fears about the blood supply are unwarranted. To date, no cases of mad cow disease have been reported in the United States. Nor has it been shown to be transmissible to humans via blood. But government officials are taking no chances. By restricting donations from frequent travelers to Britain, they have virtually eliminated the remote possibility of transfusion-related mad cow disease. That precaution is just the latest example of the ongoing improvements that make the blood supply in the United States safer than it has ever been.
, 百拇医药
Safety Guarantees
The blood supply is protected by a series of checks, tests and re-tests. The primary level of safety starts with the donor. Blood donation in the United States is voluntary and without pay. That‘s because when blood is given in exchange for money or for reasons other than altruism, the chances increase that people with a blood-borne disease might conceal their illness to reap the rewards.
Before they donate, all volunteers are asked for an extensive medical history to reveal potential exposure to disease risks. The history includes questions about foreign travel, high-risk sexual activity and intravenous drug use. The screening process is conservative to exclude anyone who might have been exposed to a blood-borne disease. For example, people who have traveled recently to an area where malaria is common will be temporarily excluded, even if they show no signs of the disease.
, 百拇医药
After giving blood, donors have an additional chance to exclude themselves by confidentially requesting that their blood not be used. That allows participation at times when donating blood seems obligatory, such as at a workplace drive or when a family member is ill. If a high-risk donor feels it would be socially awkward not to donate, he or she can go through the process and still have the blood discarded secretly afterward.
The next level of safety involves the quality of the blood itself. Every unit is put through a battery of tests to check for hepatitis B, hepatitis C, HIV (the virus that causes AIDS), HTLV-1 (a retrovirus similar to HIV) and syphilis. There are actually three tests for HIV, which allow us to identify carriers more accurately and quicker. With the current combination of tests, anyone infected with HIV would test positive within approximately 10 days of infection, as opposed to the six months that had been standard. And because most blood donors give repeatedly, their blood is tested often, further reducing the chance that a disease will slip through.
, 百拇医药
Despite those testing and safety measures, the system is not foolproof. There‘s still a risk - albeit extremely slight - of developing a transfusion-related disease. For example, the risk of acquiring HIV from a transfusion is way down, somewhere from one in 500,000 to one in 1 million per unit of blood. These numbers are considerably lower than in 1987, when the American Red Cross estimated a risk of about one in 150,000. Some rare diseases, such as malaria, may slip through simply because we are unable to test for them.
, 百拇医药
Reducing the Risk
In an emergency, donated blood may save your life. That‘s a powerful benefit to trade off against a pretty slim risk. Moreover, if you‘re facing elective surgery, you can reduce the risk of transfusion-related disease to the vanishing point by donating blood to yourself.
In the future, other risk-reducing options may become available. Researchers are investigating recombinant technology as a way of creating pharmacologic treatments that may be just as effective as human blood components. Scientists are also working on ways to sterilize platelets and red blood cells with techniques similar to those currently being used to sterilize blood plasma. That would yield blood transfusions that had been cleared of all viral activity and bacteria.
, http://www.100md.com
Another step you can take if you‘re facing surgery is to find out whether your hospital is accredited by the American Association of Blood Banks. All hospitals and blood banks are inspected by the FDA, but the AABB also conducts a voluntary inspection and offers certification to topnotch facilities. Nearly all blood centers and about two-thirds of hospitals belong to the association. Call the blood bank at your hospital and ask if it‘s accredited by the AABB. If it‘s not, discuss your safety concerns with your surgeon, and ask if there‘s an accredited hospital you can use instead., http://www.100md.com