FACTS
ABOUT BLOOD AND BLOOD BANKING
DONOR
SCREENING AND DEFERRAL
WHOLE
BLOOD AND BLOOD COMPONENTS
AUTOLOGOUS BLOOD
TESTING
OF DONOR BLOOD FOR INFECTIOUS DISEASES
TRANSFUSION-TRANSMITTED
DISEASES
VIRAL
HEPATITIS
CREUTZFELDT-JAKOB
DISEASE
HIGHLIGHTS OF
TRANSFUSION MEDICINE HISTORY
LEUKOCYTE ASSOCIATED RISKS OF
TRANSFUSION
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 32,000
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 donate each year. 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. Using current screening and
donation procedures, a growing number of blood banks have found blood donation
by seniors to be safe and practical.
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 place 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. Consult the yellow pages to locate a
nearby blood center or hospital to donate.
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.
Nearly all blood used for transfusion in the United States is drawn from
volunteer donors. 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 Apheresis?
An increasingly common procedure is apheresis, or the process of
removing a specific component of the blood, such as platelets, and returning
the remaining components, such as Red Blood Cells and Plasma, to the donor.
This process allows more of one particular part of the blood to be collected
than could be separated from a unit of Whole Blood. Apheresis is also
performed to collect Plasma (liquid part of the blood) and Granulocytes (White
Blood Cells).
The apheresis donation procedure takes longer than Whole Blood donation. A
Whole Blood donation takes about 10-20 minutes to collect the blood,
while an apheresis donation may take about one to two hours.
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 |
| O |
Rh-negative ............................. |
7 percent |
| A |
Rh-positive .............................. |
34 percent |
| A |
Rh-negative ............................. |
6 percent |
| B |
Rh-positive .............................. |
9 percent |
| B |
Rh-negative ............................. |
2 percent |
| AB |
Rh-positive .............................. |
3 percent |
| AB |
Rh-negative .............................
|
1 percent |
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 are also
performed for evidence of donor infection with 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.
How is blood stored and used?
Each unit of whole blood is normally separated into several components.
Red Blood Cells may be stored under refrigeration for a maximum of 42
days, or they may be frozen for up to 10 years. Red cells carry oxygen and are
used to treat anemia. Platelets are important in the control of
bleeding and are generally used in patients with leukemia and other forms of
cancer. Platelets are stored at room temperature and may be kept for a maximum
of five days. Fresh Frozen Plasma, used to control bleeding due to low
levels of some clotting factors, is usually kept in the frozen state for up to
one year. Cryoprecipitated AHF, which contains only a few specific
clotting factors, is made from Fresh Frozen Plasma and may be stored frozen
for up to one year. Granulocytes are sometimes used to fight
infections, although their efficacy is not well-established. They must be
transfused within 24 hours of donation.
Other products manufactured from blood include albumin, immune globulin,
specific immune globulins and clotting factor concentrates. These blood
products are commonly made by commercial manufacturers.
What fees are associated with blood?
While donated blood is free, there are significant costs associated with
collecting, testing, preparing components, storing and shipping blood,
recruiting and educating donors and quality assurance. As a result, processing
fees are charged to recover costs. Processing fees for the individual blood
components vary considerably. Processing fees for one specific component may
also vary in different geographic regions. Hospitals charge for any additional
testing that may be required, such as the crossmatch, as well as for the
administration of the blood.
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, they 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.
DONOR SCREENING AND DEFERRAL
Background
The American Association of Blood Banks (AABB) and its members are
committed to ensuring a safe and adequate blood supply for the American
people. A critical first step in the safety process is ensuring that blood
only from healthy donors enters the blood supply. Nearly all blood used for
transfusion in the United States is drawn from volunteer donors who are not
paid for the donation, a trend that was formalized in the early 1970s. Before
giving blood, donors are questioned about their health and risk factors for
disease and are given an abbreviated medical examination.
The Donation Process
Education
When prospective donors enter a blood bank, they are asked to read
educational materials such as the AABB pamphlet entitled “An Important Message
to All Blood Donors.” These materials contain information on the risks of
infectious diseases transmitted by blood transfusion, including the signs and
symptoms of AIDS. Prospective donors are asked to acknowledge in writing that
they have read and understood these materials, have been given the opportunity
to ask questions, and have provided accurate information. The prospective
donor can elect to leave at this point without donating. (Self-deferral can
occur at any point in the donation process when a donor voluntarily chooses
not to complete the process.)
Health History
If the prospective donor does not self-defer, he or she proceeds to the
next step – giving a detailed health history. The history is designed to ask
questions that protect the health of both the donor and the recipient. To
ensure that every donor is asked the same questions, the AABB recommends use
of a uniform donor history questionnaire. However, donor centers often create
their own questionnaires using the same general guidelines. In addition to
questions about transfusion-transmissible diseases, prospective donors are
asked questions to determine whether donating blood might endanger their
health. If a prospective donor responds positively to any of these questions,
he or she will be “deferred” or asked not to donate blood. The health history
is also used to identify prospective donors who have been exposed to, or who
may have diseases such as, human immunodeficiency virus (HIV), hepatitis or
malaria. These individuals are further evaluated and may be deferred.
Physical Examination
The next step in the donation process is an abbreviated physical
examination that includes checking the blood pressure, pulse and temperature.
A few drops of blood are taken from a finger or an earlobe to ensure that
anemia is not present. Abnormalities found in any part of the physical
examination may be a cause for deferral.
The Actual Donation
Prospective donors who pass successfully through these steps proceed to the
actual whole blood donation process, which takes about 20 minutes. The donor
sits in a reclining chair. The skin covering the inner part of the elbow joint
is cleansed. A new, sterile needle connected to plastic tubing and a blood bag
is inserted into an arm vein. The donor is asked to repeatedly squeeze his or
her hand to help blood flow from the vein into the blood bag. Typically, one
unit of blood, roughly equivalent to a pint, is collected. After the blood is
collected, it is sent to the laboratory for testing and component preparation.
The donor is escorted to an observation area for light refreshments and a
brief rest period.
Adult males have about 12 pints of blood in their circulation and adult
females have about nine pints. The donor's body replenishes the fluid lost
from donation in about 24 hours. The Red Blood Cells that are lost are
generally replaced in a few weeks. Whole Blood can be donated once every eight
weeks.
The Deferral Process
Individuals who are disqualified as blood donors are said to be “deferred.”
A prospective donor may be deferred at any point during the collection and
testing process. Whether or not a person is deferred temporarily or
permanently will depend on the specific reason for disqualification (eg, a
person may be deferred temporarily because of anemia, a condition that is
usually reversible). If a person is to be deferred for the protection of the
blood recipient, his or her name is entered into a list of deferred donors
maintained by the blood center, often known as the “deferral registry.” If a
deferred donor attempts to give blood before the end of the deferral period,
the donor would not be accepted for donation. At the end of a temporary
deferral period, the donor may return to the blood bank, and, if the reason
for the original deferral no longer exists, can be re-entered into the system.
AUTOLOGOUS BLOOD AS AN ALTERNATIVE
TO ALLOGENEIC BLOOD
TRANSFUSION
“Autologous” transfusions refer to those transfusions in which the
blood donor and transfusion recipient are the same. “Allogeneic”
transfusions refer to blood transfused to someone other than the donor.
Preoperative Donation
The most common autologous donation is the preoperative donation of blood
for possible transfusion back to the donor during elective surgery. For
example, a person might give one unit of blood each week for up to six weeks
before surgery, because blood can be stored in its liquid form for up to 42
days. Preoperative autologous donation is not allowed within 72 hours of
surgery due to the time needed for recovery from donation. A significant
amount of iron is removed with each autologous donation. When appropriate,
iron supplements are prescribed for patients making autologous donations to
help increase red blood cell count.
Autologous donation is most often employed in surgery on bones, blood
vessels, the urinary tract and the heart, when the likelihood of transfusion
is high. Recent data indicate that autologous blood accounts for 4.6 percent
of all donated blood. Potential autologous blood donors are medically stable
patients who are free of infection. There is no age limitation for autologous
donation. Many children and elderly patients have successfully completed
autologous donations; however, some patients may not be good candidates. The
decision regarding autologous donation and transfusion should be made jointly
by the physician and the patient.
The process of donating autologous blood stimulates the bone marrow to
produce new blood cells. Given adequate time for recovery, the collected cells
may be wholly or partially replaced prior to surgery. If blood loss is less
than anticipated, transfusion of autologous blood may not be medically
necessary. Although the risk of a complication from autologous blood is low,
some residual risk persists making automatic transfusion of autologous units
unwise. Almost one-half of autologous donations are unused. These units are
discarded since current standards do not allow transfusion of these units to
another patient for safety reasons. Due to the special handling and separate
storage requirements, autologous donations cost more to process.
Blood Dilution (Hemodilution)
Blood dilution, or hemodilution, is the removal of one or more units of
blood just before surgery for transfusion to the patient during or at the end
of the operation. Hemodilution is used
to decrease the loss of Red Blood Cells during surgery. In this procedure,
blood is drawn from a patient prior to surgery, and the patient is immediately
given intravenous fluids to compensate for the amount of blood removed. Since
the number of Red Blood Cells in the person's circulatory system has been
diluted, fewer Red Blood Cells will be lost from bleeding during the
operation. After surgery, the patient’s own blood is reinfused. However, the
patient must be able to accommodate the anemia that the procedure causes.
Intraoperative Blood Collection
In intraoperative blood collection, blood lost by the patient during
surgery is recovered and recycled throughout the surgery. Most intraoperative
blood collection programs use machines in which shed blood is collected and
the Red Blood Cells are concentrated and washed prior to transfusion. This
procedure is widely used for surgical procedures, such as cardiac, vascular,
orthopedic, urologic, trauma, gynecologic and transplant surgery, in which the
anticipated blood loss is 20 percent or more of the patient's estimated blood
volume and there is no contamination of the area by bacteria or cancer cells.
This procedure is generally not used in cancer surgery or surgery of the lower
gastrointestinal tract.
Postoperative Blood Collection
In postoperative blood collection, blood that is lost in the early
postoperative period is collected from a drainage tube at the surgical site
and transfused to the patient, either washed or unwashed. Postoperative
collection is used primarily in cardiac and orthopedic surgery. In most cases,
though, the volume of salvaged red cells is small.
TESTING OF DONOR BLOOD FOR INFECTIOUS DISEASES
Background
The American Association of Blood Banks (AABB) and its members are
committed to ensuring a safe and adequate blood supply for transfusion
recipients. Through its many publications, especially Standards for Blood
Banks and Transfusion Services, and its extensive educational programs,
the AABB has become an internationally recognized authority on blood safety
and transfusion practices. As a result of the AABB’s promotion of a
multi-tiered blood donor screening system, which includes questioning of
donors, donor deferral and promotion of state-of-the-art testing,
transfusion-transmission of infectious diseases has diminished greatly over
the years.
An important step in this safety system is the screening of donated blood
for possible infectious diseases. Today, nine tests for infectious diseases
are conducted on each unit of donated blood. Tests for hepatitis B and
syphilis were in place before 1985. Since then, tests for Human
Immunodeficiency Virus (HIV), Human T-Lymphotropic Virus (HTLV) and the
Hepatitis C Virus (HCV) have been added. The following tests are performed on
each unit of blood:
Hepatitis B Surface Antigen (HBsAg)
The hepatitis B virus, which mainly infects the liver, has an inner core
and an outer envelope (the surface). The HBsAg test detects the outer envelope
that would identify an individual infected with the hepatitis B virus.
Hepatitis B can cause inflammation of the liver, and in the earliest stage of
the disease, infected people may feel ill or even have yellow discoloration of
the skin or eyes, known as jaundice. Fortunately, most patients
recover completely and test negative for HBsAg approximately four months after
the illness. A small percentage of people may become chronic carriers of the
virus, and in these cases, the test may remain positive for months or even
years.
Antibodies to the Hepatitis B Core (Anti-HBc)
The anti-HBc test detects an antibody to the hepatitis B virus that is
produced during and after infection. If an individual has a positive anti-HBc
test, but the HBsAg test is negative, it usually means that the person once
had hepatitis B, but has recovered from the infection. Of the individuals with
a positive test for anti-HBc, many have not been exposed to the hepatitis B
virus. This kind of test result is called a false positive, and
although the individual may be permanently deferred from donating blood, it is
unlikely that the person’s health will be negatively affected. (Note: This
antibody is not produced following vaccination to hepatitis B. Hepatitis B
vaccination, by itself, will not cause one of the blood screening tests to
turn positive.)
Antibodies to the Hepatitis C Virus (Anti-HCV)
This test is used to screen donors for the hepatitis C virus (HCV). It
works by detecting antibodies manufactured by the body in reaction to portions
of the virus called antigens. HCV causes inflammation of the
liver, and up to 80 percent of those exposed to the virus develop chronic
hepatitis. Eventually, up to 20 percent of people with HCV may develop
cirrhosis of the liver or other severe liver diseases. As in other forms of
hepatitis, individuals may be infected with the virus, but may not realize
they are carriers since they do not display any symptoms. Drug therapy for
persons with chronic hepatitis C may be effective in some cases. Chronic
hepatitis C carriers benefit from avoiding alcohol and medications that can
harm the liver.
Antibodies to the Human Immunodeficiency Virus, Types 1 and 2 (Anti-HIV-1,
-2)
This test is designed to detect antibodies directed against antigens of the
HIV-1 or HIV-2 viruses. HIV-1 is much more common in the United States,
whereas HIV-2 is more prevalent in Western Africa. However, donors are tested
for both viruses because both are transmitted by infected blood, and a few
cases of HIV-2 have been identified in US residents. Both of these viruses can
cause acquired immunodeficiency syndrome, or AIDS.
HIV-1 p24 Antigen
This test screens for antigens of the HIV-1 virus. The extra safety added
by doing this test derives from its ability to detect HIV-1 infection a week
earlier than the antibody test. Thus, the HIV-1 infection can be identified
sooner, and the risk of getting HIV-1 from a blood transfusion is decreased to
1 in 825,000 units of screened blood (As reported in a December 1995 study
published in the New England Journal of Medicine).
Antibodies to Human T-Lymphotropic Virus, Types I and II (Anti-HTLV-I,
-II)
This test screens for antibodies directed against portions of the HTLV-I
and HTLV-II viruses. Both of these viruses are relatively uncommon in the
United States, but do occur more frequently in certain populations. HTLV-I is
more common in Japan and the Caribbean. The infection can persist for a
lifetime, but rarely causes major illnesses in most people who are infected.
In rare instances, the virus may eventually cause nervous system disease or an
unusual type of leukemia. HTLV-II infections are usually associated with
intravenous drug usage, especially among people who share needles or syringes.
Syphilis
This test is done to detect evidence of infection with the bacterium,
called spirochete, that causes syphilis. Blood centers began
testing for this shortly after World War II, when syphilis rates in the
general population were much higher. The risk of transmitting syphilis through
a blood transfusion is exceedingly small because the infection is very rare in
blood donors, and because the spirochete is fragile and unlikely to survive
blood storage conditions.
Nucleic Acid Amplification Testing (NAT)
NAT employs a new form of testing technology that directly detects the
genetic material of viruses like HCV and HIV. Because NAT detects the genetic
material of a virus, instead of having to wait for the human body’s response
to a virus—the formation of antibodies against it, as is the case with most
current tests—it offers the potential advantage over the current tests of
reducing the window period, thus further improving blood safety.
Several issues must be resolved before NAT can be implemented for all
voluntary blood donations. The use of NAT has not yet been approved by the FDA
for donor screening in the US. Because of the promise that this technology
holds for even further improving the safety of the blood supply, many blood
collection organizations are pursuing the implementation of NAT under the
FDA’s Investigational New Drug (IND) application process. This process will
allow blood collectors to conduct NAT under certain guidelines so that they,
and the FDA, can track the progress of this research initiative.
Confirmatory Testing
All of the above tests are referred to as screening tests,
and are designed to detect as many infections as possible. Because these tests
are so sensitive, some donors may have a false positive result, even if they
were never exposed to the particular infection. In order to sort out true
infections from false positive test results, screening tests that are reactive
may be followed up with more specific tests called confirmatory
tests. Thus, confirmatory tests help determine whether a donor is
truly infected.
If the test result from a donated unit of blood is abnormal for any of
these disease markers, the unit is discarded.
TRANSFUSION-TRANSMITTED DISEASES
Background
The American Association of Blood Banks (AABB) and its members are
committed to ensuring a safe and adequate blood supply for transfusion
recipients. Through its many publications, especially Standards for Blood
Banks and Transfusion Services, and its extensive educational programs,
the AABB has become an internationally recognized authority on blood safety
and transfusion practices. As a result of AABB’s promotion of a multi-tiered
blood donor screening system, which includes questioning of donors, donor
deferral and promotion of state-of-the-art testing, transfusion-transmission
of infectious diseases has diminished greatly over the years.
Viruses
Human Immunodeficiency Virus (HIV)
Transfusion transmission of HIV, the virus that causes AIDS, has been
almost completely eradicated. Since early 1985, blood centers have tested
every blood donation for HIV antibodies. HIV tests have undergone continuous
improvement, and in 1996 blood centers added yet another HIV test called the
HIV antigen assay. This new test makes the blood supply even safer, because it
can detect HIV about one week sooner than the antibody test. Used in
combination, these sophisticated tests have reduced the risk of getting HIV
from a single blood transfusion to about 1 in 676,000. Transfusion medicine
specialists are continually researching new technologies to further reduce the
transmission of HIV. Examples of technologies that are on the horizon include
tests for HIV gene material, methods to kill viruses in donated blood (called
viral inactivation) and blood component substitutes.
Human T Lymphotropic Virus I, -II (HTLV-I, -II)
HTLV-I and -II are unusual viruses that are not related to HIV. HTLV-I is
found mainly in Southwestern Japan and Caribbean islands. The virus may
eventually cause blood or nervous system diseases in a very small number of
infected people. HTLV-II is endemic in the Americas (including the US), and
may also infrequently cause nervous system disease. Both of these viruses,
although rare, were found in the US blood donor population in the 1980s. Few
people have gotten HTLV as a result of transfusion, but because of the small
transfusion risk that existed in the 1980s, tests to detect HTLV-I antibodies
were developed and quickly implemented; these tests also detected many HTLV-II
infections. Tests that are specifically designed to detect both viruses are
now available and are used by blood centers to screen every donation.
Cytomegalovirus (CMV)
Cytomegalovirus (CMV) is a virus belonging to the herpes group that can be
transmitted by blood transfusion. About one percent of the blood donor
population test positive for antibodies to the virus, and less than one
percent of donors appear able to transmit the infection. CMV infection is
usually mild, but it may be serious or fatal in those who are
immunocompromised. Particularly at risk are low-birth weight infants and bone
marrow and heart-lung transplant patients. If a patient is at high risk of
getting CMV diseases, blood that tests negative for CMV can be transfused.
Alternatively, blood that has been filtered to decrease the number of White
Blood Cells – the cells that carry CMV – may protect patients from getting a
CMV infection from transfusion.
Parasitic Infections
Malaria
Of an estimated four million patients who are transfused each year, only
about three cases of transfusion-transmitted malaria are reported in the US.
These cases are usually caused by someone who feels well and does not know he
or she is carrying malaria. Although exceedingly rare, malaria can cause
serious consequences, including fatalities. The AABB requires blood centers to
temporarily defer blood donations from people who have visited malarial areas
in the past year or who emigrated from a malarial area within the past three
years.
Babesiosis
Babesiosis is a parasitic infection that is carried by the white-footed
mouse and transmitted by tick bites. It appears primarily in the Northeastern
US, in coastal areas that are home to the white-footed mouse. In the past 20
years, about two dozen transfusion-associated cases have been reported in the
US. People who have been infected through tick bites can only transmit the
parasite through blood for a very short period of time after being exposed.
However, some patients, including those who do not have a spleen or whose
immunity is compromised, may be at risk of serious illness. For this reason,
the AABB requires that all donors be asked if they have a history of
babesiosis. Those individuals with a history of the disease are permanently
deferred from donating blood.
Chagas’ Disease
Chagas’ Disease was discovered almost 100 years ago by a Brazilian doctor,
Carlos Chagas. This disease is caused by a parasite that infects as many as 18
million people worldwide. Each year, several thousand South and Central
Americans die of heart and digestive problems caused by the disease. Up to 20
percent of infected people never exhibit symptoms. This infection is rare in
the US, but because of recent global population shifts, individuals from
countries where this disease is common now reside in the US. To date, there
have been only four cases of transfusion-transmitted Chagas’ disease reported
in North America. The AABB requires that blood centers permanently prohibit
blood donation from anyone who has had Chagas’ Disease.
Lyme Disease
Although transfusion-related cases have not been reported, public health
agencies and the AABB are monitoring this disease because of the remote chance
that it could affect transfusion safety. Lyme disease is associated with the
bite of certain species of the deer tick, and can cause an illness that
affects many systems within the body. Donors with a history of Lyme disease
can donate provided they have undergone a full course of antibiotic treatment
and no longer have any symptoms.
VIRAL HEPATITIS
Background
The American Association of Blood Banks (AABB) and its members are
committed to ensuring a safe and adequate blood supply for the American
people. The AABB continually takes steps to enhance safety by evaluating new
technology as it becomes available. After AABB assessment of specific
technology is deemed effective and feasible for use, its use is promoted at
the blood bank level through AABB’s Standards for Blood Banks and
Transfusion Services. As a result of the AABB’s development of a
multi-layer safety system, which includes questioning of donors and donor
deferral and testing, the incidence of transfusion-transmission of infectious
diseases has steadily diminished over the years.
Hepatitis was the first documented transfusion-transmitted disease. Many of
the current practices for diminishing risk in transfusion medicine are based
on the experiences of controlling the transmission of hepatitis. This
experience is based on the transition from paid donors to an all volunteer
blood supply in the early 1970s and improvements in blood testing.
Hepatitis viruses, which affect the liver, fall primarily into two groups:
viruses that cause acute disease and are not often transmitted by transfusion
(hepatitis A and E), and viruses with a chronic course that can readily be
transmitted by blood transfusion (hepatitis B and C).
Hepatitis A Virus (HAV)
Hepatitis A (HAV) infection is rarely transmitted through blood
transfusion; it is usually spread by contaminated food and water. About 23,000
cases are reported annually in the US, but epidemiologists estimate that the
virus infects 150,000 Americans each year. Hepatitis A is much more prevalent
elsewhere, including Mexico and parts of the Caribbean. Because HAV antibodies
are present in approximately 20 percent of the population, it is assumed that
many people experience mild or no symptoms. There have been occasional reports
in the US of transfusion-transmitted HAV, but little can be done to prevent
this rare occurrence. A vaccine recently developed for HAV is expected to
replace immune globulin as a prophylactic measure for people at a high risk
for acquiring this infection.
Hepatitis B Virus (HBV)
Transmission of hepatitis B virus (HBV) is rare because of routine testing
of blood for the HBsAg and hepatitis B core antibody, donor screening and
deferral and the use of a volunteer blood supply. HBV is a major cause of
acute and chronic hepatitis. Each year in the US, an estimated 300,000 persons
are infected with HBV. More than 10,000 patients require hospitalization and
an average of 350 die from the disease. There is an estimated pool of 750,000
- 1,000,000 infectious HBV carriers. Approximately 25 percent of carriers
develop active hepatitis, often progressing to cirrhosis of the liver. An
estimated 4,000 people die each year from hepatitis B-related cirrhosis, and
more than 800 die from hepatitis B-related liver cancer. The number of HBV
infections in the US is expected to drop with current, routine hepatitis B
vaccinations of health care professionals and school-age children.
Screening blood donors for HBV began in 1969 and became mandatory in 1972.
By the mid-1970s, testing and an all volunteer blood donor supply reduced the
rate of post transfusion hepatitis B to between 0.3 and 0.9 percent. From
1982-85, an average of 3 percent of hepatitis B cases were related to blood
transfusion. During the period 1986-88, the percentage of reported cases
related to blood transfusion declined to 1 percent, possibly as a consequence
of the donor screening questions that were instituted to identify persons at
increased risk for HIV infection.
In a small number of hepatitis B carriers, the hepatitis tests used to
screen blood will be negative, and a small number of transfusion recipients
may still develop hepatitis B. In 1996, the frequency of post-transfusion
hepatitis B developing after a blood transfusion was estimated at 1 per 66,000
screened units of blood.
Hepatitis C Virus (HCV)
Acute hepatitis C virus (HCV) is relatively mild. It has an incubation
period of about seven to eight weeks. However, post-transfusion infection with
HCV most often becomes chronic. Among the general population today, at any one
time, 1 percent of the population has HCV antibodies present. There are an
estimated 150,000 - 170,000 new HCV infections annually in the US. Although
chronic liver disease is a frequent result of HCV, such disease may take years
to develop. The majority of people with chronic HCV infection may be
asymptomatic.
For many years, HCV occurred among 5 percent or more of all blood
recipients. In 1991, the incidence of transfusion-related HCV occurred in 1 to
4 percent of transfusion recipients. Today, after more than seven years of
testing for HCV, the risk of HCV transmission through transfusion is less than
1 per 100,000 screened units of blood.
With the implementation of nucleic acid amplification testing (NAT), the
risk of receiving HCV from a unit of blood may be reduced to 1 per 500,000 to
1 per 1,000,000. NAT is still a research initiative and the degree to which
safety may be affected is not yet known (See Testing of Donor Blood for
Infectious Disease fact sheet).
Hepatitis E Virus (HEV)
Like HAV, hepatitis E virus is a food and water-borne form of hepatitis
that has resulted in outbreaks in India, other parts of the Asian subcontinent
and South America. Hepatitis E virus has not been a problem in the United
States and Canada.
Hepatitis G Virus (HGV)
A new virus, provisionally designated hepatitis G virus (HGV), was
described in 1996 and later reported to be present in approximately two
percent of US blood donors. Although the virus may be transmitted through
transfusion, the association of HGV infection with liver disease remains
tenuous. The majority of people who carry the virus appear to have no liver
abnormalities. The absence of significant liver disease suggests that
transmission of the virus may not greatly undermine the safety of the blood
supply. Presently, blood donors are not routinely tested for HGV because a
mass screening test does not exist and HGV infection has not been convincingly
incriminated with a specific disease association.
Other Hepatitis Viruses
There are hepatitis viruses which are being researched by the blood banking
and transfusion medicine community. One of these, Hepatitis D virus (HDV),
causes infection only in the presence of HBV. Individuals who are infected
with both HBV and HDV are at a much more serious risk for disease progression.
However, testing to detect the presence of hepatitis B should prevent these
infections by blood transfusion.
Other viruses, such as cytomegalovirus (CMV) and Epstein-Barr virus (EBV)
may also cause inflammation of the liver (hepatitis). Hepatitis may result
from non-viral causes as well.
CREUTZFELDT-JAKOB DISEASE
Background
The American Association of Blood Banks (AABB) and its members are
committed to ensuring a safe and adequate blood supply for the American
people. The AABB continually takes steps to enhance safety by evaluating new
technology, as it becomes available. Through its many publications, especially
Standards for Blood Banks and Transfusion Services, and its extensive
educational programs, the AABB has become an internationally recognized
authority on blood safety and transfusion practices. As a result of AABB’s
promotion of a multi-tiered blood donor screening system, which includes
questioning of donors, donor deferral and promotion of state-of-the-art
testing, transfusion-transmission of infectious diseases has diminished
greatly over the years.
Creutzfeldt-Jakob Disease (CJD)
Blood transfusions have never been shown to transmit Creutzfeldt-Jakob
disease (CJD). CJD is a rare, degenerative and fatal nervous system disorder.
Affected individuals can remain asymptomatic for decades and then progress
rapidly to dementia, severe loss of coordination and death. CJD rarely has
been transmitted to individuals who received injections of human pituitary
gland growth hormone, or who have had their brain’s outer lining (dura mater)
repaired with dura mater from someone else who had CJD. Scientists believe
abnormal brain proteins that have undergone a peculiar shape change can cause
other brain proteins to do the same and cause CJD. Currently, there is no test
for the disease, but the AABB prohibits blood donation by individuals who have
received injections of human-derived pituitary hormone. Donors are also
questioned about family history of CJD and surgeries that involved
transplanted dura mater. If they answer affirmatively to any of these
questions, they are never permitted to donate blood.
New Variant Creutzfeldt-Jakob Disease (nvCJD)
Similar to CJD, nvCJD is a rare, degenerative and fatal nervous system
disorder that has never been shown to be transmitted by blood transfusion.
Most affected individuals were residents of the United Kingdom. Currently,
there is no test for the disease, but the FDA prohibits blood donation by
individuals who have resided in the United Kingdom for a cumulative period of
six months or more from 1980-1996.
HIGHLIGHTS OF TRANSFUSION MEDICINE HISTORY
1628 English physician William Harvey discovers the circulation of
blood. Shortly afterward, the earliest known blood transfusion is attempted.
1665 The first recorded successful blood transfusion occurs in
England: Physician Richard Lower keeps dogs alive by transfusion of blood from
other dogs.
1667 Jean-Baptiste Denis in France and Richard Lower in England
separately report successful transfusions from lambs to humans. Within 10
years, transfusing the blood of animals to humans becomes prohibited by law
because of reactions.
1795 In Philadelphia an American physician, Philip Syng Physick,
performs the first human blood transfusion, although he does not publish this
information.
1818 James Blundell, a British obstetrician, performs the first
successful transfusion of human blood to a patient for the treatment of
postpartum hemorrhage. Using the patient's husband as a donor, he extracts
approximately four ounces of blood from the husband's arm and, using a
syringe, successfully transfuses the wife. Between 1825 and 1830, he performs
10 transfusions, five of which prove beneficial to his patients, and publishes
these results. He also devises various instruments for performing transfusions
and proposed rational indications.
1840 At St. George's School in London, Samuel Armstrong Lane, aided
by consultant Dr. Blundell, performs the first successful whole blood
transfusion to treat hemophilia.
1867 English surgeon Joseph Lister uses antiseptics to control
infection during transfusions.
1873-1880 US physicians transfused milk (from cows, goats and
humans).
1884 Saline infusion replaces milk as a “blood substitute” due to
the increased frequency of adverse reactions to milk.
1900 Karl Landsteiner, an Austrian physician, discovers the first
three human blood groups, A, B and O. The fourth, AB, is added by his
colleagues A. Decastello and A. Sturli in 1902. Landsteiner receives the Nobel
Prize for Medicine for this discovery in 1930.
1907 Hektoen suggests that the safety of transfusion might be
improved by crossmatching blood between donors and patients to exclude
incompatible mixtures. Reuben Ottenberg performs the first blood transfusion
using blood typing and crossmatching in New York. Ottenberg also observed the
mendelian inheritance of blood groups and recognized the “universal” utility
of group O donors.
1908 French surgeon Alexis Carrel devises a way to prevent clotting
by sewing the vein of the recipient directly to the artery of the donor. This
vein-to-vein or direct method, known as anastomosis, is practiced by a
number of physicians, among them J.B. Murphy in Chicago and George Crile in
Cleveland. The procedure, however, proves unfeasible for blood transfusions,
but paves the way for successful organ transplantation, for which Carrel
receives the Nobel Prize in 1912.
1908 Moreschi describes the antiglobulin reaction.
1912 Roger Lee, a visiting physician at the Massachusetts General
Hospital, along with Paul Dudley White, develops the Lee-White clotting time.
Adding another important discovery to the growing body of knowledge of
transfusion medicine, Lee demonstrates that it is safe to give group O blood
to patients of any blood group, and that blood from all groups can be given to
group AB patients. The terms "universal donor" and "universal recipient" are
coined.
1914 Long-term anticoagulants, among them sodium citrate, are
developed, allowing longer preservation of blood.
1915 At Mt. Sinai Hospital in New York, Richard Lewisohn uses sodium
citrate as an anticoagulant to transform the transfusion procedure from direct
to indirect. In addition, R. Weil demonstrates the feasibility of refrigerated
storage of such anticoagulated blood. Although this is a great advance in
transfusion medicine, it takes 10 years for sodium citrate use to be accepted.
1916 Francis Rous and J.R. Turner introduce a citrate-glucose
solution that permits storage of blood for several days after collection.
Allowing for blood to be stored in containers for later transfusion aids the
transition from the vein-to-vein method to direct transfusion. This discovery
also allows for the establishment of the first blood depot by the British
during World War I. Oswald Robertson is credited as the creator of the blood
depots.
1927-1947 The MNSs and P systems are discovered.
1932 The first blood bank is established in a Leningrad
hospital.
1937 Bernard Fantus, director of therapeutics at the Cook County
Hospital in Chicago, establishes the first hospital blood bank. In creating a
hospital laboratory that can preserve and store donor blood, Fantus originates
the term "blood bank." Within a few years, hospital and community blood banks
begin to be established across the United States. Some of the earliest are in
San Francisco, New York, Miami and Cincinnati.
1939/40 The Rh blood group system is discovered by Karl Landsteiner,
Alex Wiener, Philip Levine and R.E. Stetson and is soon recognized as the
cause of the majority of transfusion reactions. Identification of the Rh
factor takes its place next to ABO as one of the most important breakthroughs
in the field of blood banking.
1940 Edwin Cohn, a professor of biological chemistry at Harvard
Medical School, develops cold ethanol fractionation, the process of breaking
down plasma into components and products. Albumin, a protein with powerful
osmotic properties, plus gamma globulin and fibrinogen are isolated and become
available for clinical use. The efficacy of albumin in transfusion is
demonstrated by John Elliott.
1940 The United States government established a nationwide program
for the collection of blood. Charles R. Drew develops the “Plasma for Britain”
program. The American Red Cross participates, collecting 13 million units of
blood by the end of World War II.
1941 Isodor Ravdin, a prominent surgeon from Philadelphia,
effectively treats victims of the Pearl Harbor attack with Cohn's albumin for
shock. Injected into the blood stream, albumin absorbs liquid from surrounding
tissues, preventing blood vessels from collapsing, a finding associated with
shock.
1943 The introduction by J.F. Loutit and Patrick L. Mollison of acid
citrate dextrose (ACD) solution, which reduces the volume of anticoagulant,
permits transfusions of greater volumes of blood and permits longer term
storage.
1943 P. Beeson publishes the classic description of
transfusion-transmitted hepatitis.
1945 Coombs, Mourant and Race describe the use of antihuman globulin
(later known as the “Coombs Test”) to identify “incomplete” antibodies.
1947 The American Association of Blood Banks (AABB) is formed to
promote common goals among blood banking practitioners and the blood donating
public.
1949-1950 The US blood collection system includes 1500 hospital
blood banks, 46 community blood centers and 31 American Red Cross regional
blood centers.
1950 Audrey Smith reports the use of glycerol cryoprotectant for
freezing Red Blood Cells.
1950 In one of the single most influential technical developments in
blood banking, Carl Walter and W.P. Murphy, Jr., introduce the plastic bag for
blood collection. Replacing breakable glass bottles with durable plastic bags
allows for the evolution of a collection system capable of safe and easy
preparation of multiple blood components from a single unit of whole blood.
Development of the refrigerated centrifuge in 1953 further expedites blood
component therapy.
1951 The AABB Clearinghouse is established, providing a centralized
system for exchanging blood among blood banks. Today, the Clearinghouse is
called the National Blood Exchange.
Mid-1950s In response to the heightened demand created by open heart
surgery and advances in trauma care patients, blood use enters its most
explosive growth period.
1957 The AABB forms its committee on Inspection and Accreditation to
monitor the implementation of standards for blood banking.
1958 The AABB publishes its first edition of Standards for a
Blood Transfusion Service (now titled Standards for Blood Banks and
Transfusion Services).
1959 Max Perutz of Cambridge University deciphers the molecular
structure of hemoglobin, the molecule that transports oxygen and gives Red
Blood Cells their color.
1960 The AABB begins publication of TRANSFUSION, the first
American journal wholly devoted to the science of blood banking and
transfusion technology. In this same year, A. Solomon and J.L. Fahey report
the first therapeutic plasmapheresis procedure.
1961 The role of platelet concentrates in reducing mortality from
hemorrhage in cancer patients is recognized.
1962 The first antihemophilic factor (AHF) concentrate to treat
coagulation disorders in hemophilia patients is developed through
fractionation.
1962 In the US, there were 4400 hospital blood banks, 123 community
blood centers and 55 American Red Cross blood centers, collecting a total of
five to six million units of blood per year.
1964 Plasmapheresis is introduced as a means of collecting Plasma
for fractionation.
1965 Judith G. Pool and Angela E. Shannon report a method for
producing Cryoprecipitated AHF for treatment of hemophilia.
1967 Rh immune globulin is commercially introduced to prevent Rh
disease in the newborns of Rh-negative women.
1969 S. Murphy and F. Gardner demonstrate the feasibility of storing
Platelets at room temperature, revolutionizing platelet transfusion therapy.
1970 Blood banks move toward an all-volunteer blood donor
system.
1971 Hepatitis B surface antigen (HBsAg) testing of donated blood
begins.
1972 Apheresis is used to extract one cellular component, returning
the rest of the blood to the donor.
1979 A new anticoagulant preservative, CPDA-1, extends the shelf
life of Whole Blood and Red Blood Cells to 35 days, increasing the blood
supply and facilitating resource sharing among blood banks.
Early 1980s With the growth of component therapy, products for
coagulation disorders and plasma exchange for the treatment of autoimmune
disorders, hospital and community blood banks enter the era of transfusion
medicine, in which doctors trained specifically in blood transfusion actively
participate in patient care.
1983 Additive solutions extend the shelf life of Red Blood Cells to
42 days.
1985 The first blood screening test to detect HIV is licensed and
quickly implemented by blood banks to protect the blood supply.
1987 Two tests for screening for indirect evidence of hepatitis C
are developed and implemented, hepatitis B core antibody (anti-HBc) and the
alanine aminotransferase test (ALT).
1989 Human T Lymphotropic Virus I antibody (anti-HTLV-I) testing of
donated blood begins.
1990 Introduction of first specific test for hepatitis C, the major
cause of “non-A, non-B” hepatitis, although the hepatitis C virus (HCV) has
never been isolated.
1992 Testing of donor blood for HIV-1 and HIV-2 antibodies
(anti-HIV-1 and anti-HIV-2) is implemented.
1996 HIV p24 antigen testing of donated blood begins. Although the
test does not completely close the HIV window, it shortens the window period.
1997 US Government issues two reports suggesting ways to improve
blood safety, including regulatory reform.
1998 HCV lookback campaign begins.
1999 Blood community begins implementation of Nucleic Acid
Amplification Testing (NAT) under the FDA’s Investigational New Drug (IND)
application process. NAT employs a testing technology that directly detects
the genetic materials of viruses like HCV and HIV.
