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Got
Questions About Blood? / Facts About Blood And Blood Banking
How much blood is donated each year?
How much blood is transfused each year?*
About 12.6 million units (including approximately 643,000 autologous
donations) of whole blood are
donated in the United States each year by approximately eight million
volunteer blood donors. These units are transfused to about four million
patients per year.
Typically,
each donated unit of blood, referred to as whole blood, is separated into
multiple components, such as red blood
cells, plasma, and platelets. Each component is generally transfused
to a different individual, each with different needs.
The need for
blood is great--on any given day, approximately 34,000 units of red blood
cells are needed. Accident victims, people undergoing surgery, and
patients receiving treatment for leukemia, cancer, or other diseases, such
as sickle cell disease and thalassemia, all utilize blood. More than 23
million units of blood components are transfused every year.
Who donates blood?
Less than 5 percent of healthy Americans eligible to
donate blood, actually do
so. According to studies, the average donor is a college-educated white
male, between the ages of 30 and 50, who is married and has an
above-average income. However, a broad cross-section of the population
donates every day. Furthermore, these “average” statistics are changing,
and women and minority groups are volunteering to donate in increasing
numbers. While persons 65 years and older compose 13 percent of the
population, they use 25 percent of all blood units transfused.
Patients
scheduled for surgery may be eligible to donate blood for themselves, a
process known as autologous blood donation. In the weeks before
non-emergency surgery, an autologous donor may be able to donate blood
that will be stored until the surgical procedure.
Where is blood donated?
There are many places where blood donations can be made. Bloodmobiles
(mobile blood drives on specially constructed buses) travel to high
schools, colleges, churches, and community organizations. People can also
donate at community blood
centers and hospital-based donor centers. Many people donate at blood
drives at their places of work. Community blood centers collect
approximately 88 percent of the nation's blood, and hospital-based donor
centers account for the other 12 percent.
What are the criteria for blood donation?
To be eligible to donate
blood, a person must generally be at least 17 years of age (although
some states permit younger people to donate with parental consent); be in
good health; and weigh at least 110 pounds. Most blood banks have no upper
age limit. All donors must pass the physical and health history
examinations given prior to donation.
The donor’s
body replenishes the fluid lost from donation in 24 hours. It may take up
to two months to replace the lost red blood cells. Whole blood can be
donated once every eight weeks.
What is the most common blood type?
The approximate distribution of blood types in the US population is as
follows. Distribution may be different for specific racial and ethnic
groups:
O Rh-positive
38 percent |
B Rh-positive
9 percent |
O Rh-negative
7 percent |
B Rh-negative
2 percent |
A Rh-positive
34 percent |
AB Rh-positive
3 percent |
A Rh-negative
6 percent |
AB Rh-negative
1 percent |
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In an
emergency, anyone can receive type O red blood cells, and type AB
individuals can receive red blood cells of any ABO type. Therefore, people
with type O blood are known as “universal donors” and those with type AB
blood are known as “universal recipients.” In addition, AB Plasma donors
can give to all blood types.
What tests are performed on donated blood?
After blood is drawn, it is tested for ABO group (blood type) and Rh type
(positive or negative), as well as for any unexpected red blood cell
antibodies that may cause problems in the recipient. Screening tests also
are performed for evidence of donor infection, such as hepatitis viruses B
and C, human immunodeficiency viruses (HIV) 1 and 2, human T-lymphotropic
viruses (HTLV) I and II, and syphilis. The specific tests performed are
listed below:
- Hepatitis B
surface antigen (HBsAg)
- Hepatitis B
core antibody (anti-HBc)
- Hepatitis C
virus antibody (anti-HCV)
- HIV-1 and
HIV-2 antibody (anti-HIV-1 and anti-HIV-2)
- HIV p24
antigen
- HTLV-I and
HTLV-II antibody (anti-HTLV-I and anti-HTLV-II)
- Serologic
test for syphilis
- Nucleic
Acid Amplification Testing (NAT)
Note: NAT is
still a research initiative and many blood collection organizations are
pursuing implementation under the FDA’s Investigational New Drug (IND)
application process.
When are blood donors needed most?
While blood donors are needed throughout the year, they are most needed
during holidays and in the summer. It is during these times that the
number of donations declines while the demand continues or even increases.
While a given individual may be unable to donate, he or she may be able to
recruit a suitable donor. Relatives and friends of a patient requiring a
blood transfusion may wish to help their loved one.
Donating blood to
replenish the units that were needed is one of the best gifts one can
give.
*Data provided by the National Blood Data Resource
Center for 1997.
U.S.
Food and Drug Administration
The U.S.
Food and Drug Administration (FDA) regulates and licenses
all blood banks. To learn more about federal policies related
to blood, the latest in research and other important national
information.
- Visit
the FDA's "Blood
FAQs" for answers to your blood questions.
- Visit
these other links to learn more about blood donation!
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