Ever since transfusions of contaminated blood during the late 1970s and early 1980s infected thousands of North American hemophiliacs with AIDS, rigorous safeguards have been in place at Canadian and U.S. blood clinics. But the risk remains that someone infected with the AIDS virus, who has yet to develop the antibodies that tests can detect, might donate blood. “If we have suspicions,” says Jim Soonarane, nursing manager at the Red Cross’s Toronto blood centre, “we would ask the donor to consider very, very carefully whether he should be giving blood.” That is just the beginning of the battery of measures aimed at safeguarding Canada’s blood supply. But in the view of the U.S. Food and Drug Administration (FDA), the Canadian system contains some potentially dangerous loopholes. A report filed by an FDA inspector in July and made public last week found 19 deficiencies in the Toronto blood centre’s procedures—including some that, in theory at least, could infect blood transfusion recipients with deadly diseases.
The report pointed to differences in the way American and Canadian blood clinics operate—and led to a U.S. ban on some types of blood being sent to a plant in North Carolina for processing. In some cases, the FDA criticisms focused on minor administrative flaws: the Toronto clinic, which serves 61 hospitals in southern Ontario, was faulted for issuing internal directives that were not signed by senior officials. The FDA report also pointed to sometimes casual record-keeping at the Toronto centre and a less thorough approach to donor health than FDA rules require: in Canadian clinics, donors are not weighed, nor
is their temperature and blood pressure measured—procedures that are followed in U.S. Red Cross clinics. Other criticisms contained in the FDA report investigated more sensitive areas in the screening processes designed to
protect the blood supply. One Canadian practice involving tests for the AIDS virus appears to create a small but worrying chance that contaminated blood might find its way into the body of a bloodtransfusion recipient. Among the major criticisms in the FDA report:
SCREENING DONORS: In both Canadian and American Red Cross blood clinics, staff members demand information from prospective donors about their medical history, their general health—and about whether they have engaged in high-risk behavior
that could expose them to infection by the HIV vims that is believed to cause AIDS. The procedure in U.S. Red Cross blood clinics is probably tougher than in Canada. American Red Cross staffers verbally question donors about their medical condition and about high-risk sexual activities. Men are bluntly asked: “Have you had sex with a man since 1977?” The answers are written down and recorded. In Canadian clinics, donors fill out a 17-point questionnaire that inquires about past illnesses and about high-risk activities. Only sometimes are verbal follow-up questions asked. In U.S. clinics, donors must expose their arms so that staffers can check for needle marks that would indicate intravenous drug use—another high-risk activity for HIV infection. In Canadian clinics, nurses check donors’ arms informally while blood donations are being made. On both sides of the border, donors who may have lied are given a final opportunity to come clean by answering Yes or No to a confidential question that asks whether their blood should be used in transfusions.
TESTING FOR HIV: After donors have given blood, Canadian and U.S. Red Cross clinics test a blood sample for infectious viruses, including HIV, three types of hepatitis, syphilis and the leukemia virus HTLVl. In both countries, initial screening for HIV is by a test called ELISA (for enzyme-linked immune assay)—which is quick but often inaccurate. If the ELISA test indicates the presence of HIV antibodies produced by the body’s immune system, a Western blot test—in which antibodies appear as blots on specially coated paper—is used to confirm the first finding. When the ELISA test indicates possible HIV infection of a donor’s blood, U.S. clinics immediately quarantine any unused blood previously taken from the donor. In such cases, Canadian clinics do not take action until the Western blot test confirms the ELISA finding—a procedure that can take up to two weeks. The FDA report found this practice unacceptable. In defence, Dr. Wendy Lau, deputy medical director at the Toronto blood centre, said that given the high number of false positive results produced by ELISA tests, the chance of HIV-infected blood being used in a transfusion while waiting for the Western blot results is “highly unlikely.” But, added Lau, “I can’t say that it’s impossible.”
TRACING HIV-INFECTED DONORS: When a blood transfusion recipient tests positive for HIV, the Canadian Red Cross attempts to contact and retest all donors whose blood was involved—a daunting task since blood products may contain material from hundreds of donors. When an HIV-positive donor is located, the search ends because Canadian officials believe that the chances are slim that other infected donors were involved. The FDA criticized that practice, insisting that as many donors as possible should be located and tested. Lau said that the Canadian Red Cross would probably begin to follow the U.S. practice.
SCREENING FOR HEPATITIS B: In Canadian clinics, a single method, called a surface antigen test, is used to check on the pres-
ence of the virus for hepatitis B—a sometimes fatal disease that attacks the liver. In the United States, the FDA requires blood clinics to use two hepatitis B tests—the surface antigen test and, in addition, a core antibody test. While the surface antigen method tests for the presence of the hepatitis virus, the core antibody test is used to indicate the presence of hepatitis antibodies. Canadian Red Cross officials point out that a person who has had hepatitis in the past may have fully recovered—and be free of the infectious virus—but still have antibodies in his blood. Though the FDA report criticized Canadian clinics for not using both hepatitis B tests, FDA spokesman Larry Bachorik conceded that “it’s a judgment call—the fact that Canada doesn’t use both tests should probably not be regarded as a serious deficiency.”
AUTOLOGOUS BLOOD TESTING: In some cases, people scheduled for surgery can bank blood to be used later for their own transfusions. These are called autologous transfusions. In both Canadian and U.S. blood clinics, normal screening procedures are applied to autologous donations. But under FDA rules, American clinics remove the reference to blood type from labels on bags containing autologous blood so that it is less likely to be used by mistake on anyone except the donor. In Canadian clinics, the blood type is part of the identifying number on blood bags—a procedure faulted in the FDA report. There are other differences in U.S. and Canadian autologous blood policies. In Canada, if autologous blood tests positive for HIV, it is destroyed—and the patient is transfused with uncontaminated blood. But in U.S. clinics, AIDS victims and people who are HIV-positive can bank their own HIV-infected blood for later transfusions.
DUPLICATE DONOR RECORDS: The FDA report also objected to the fact that the Toronto blood centre’s computer—unlike the American Red Cross’s computer system—is not equipped with a program to spot cases where records exist for the same donor, perhaps with slightly different spellings of the name or other details. As a result, a Canadian donor’s complete record might not be filed under a single name. According to Lau, a new computer system that can search for and spot duplications is currently under development.
There are other differences between the Canadian and American blood collection systems. In Canada, all blood collection is carried out by the Red Cross, under the supervision of Health Canada’s drug directorate. In the United States, only about half of the blood supply is in Red Cross hands. The rest is collected and distributed by community clinics, not-forprofit blood banks and hospitals. There are also about 400 centres that collect blood plasma—the fluid part of blood used in the manufacturing of specialized blood products, including clotting factors for hemophiliacs. American plasma donors are paid between $20 and $27; Canadian blood donors are never paid. But U.S. officials insist that paid plasma donors— many of them students or unemployed workers—are strictly screened. “Our safety procedures are second to none,” says James Reilly, president of Annapolis, Md.-based American Blood Resources Association. Now, efforts by the Canadian Red Cross to correct the problems spotlighted by the FDA report should ensure that the nation’s blood supply measures up to the same lofty standards.
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