Case Study Week 2
PART I In December 1982, a report in the MMWR described three persons who had developed
acquired immunodeficiency syndrome (AIDS) but
... [Show More] who had neither of the previously known risk
factors for the disease: homosexual/bisexual activity with numerous partners and intravenous
drug use. These three persons had previously received whole-blood transfusions. By 1983,
widespread recognition of the problem of transfusion-related AIDS led to controversial
recommendations that persons in known high-risk groups voluntarily defer from donating blood.
In June 1984, after the discovery of the human immunodeficiency virus (HIV), five companies
were licensed to produce enzyme-linked immunosorbent assay (EIA, then called ELISA) test kits
for detecting HIV antibody. A Food and Drug Administration (FDA) spokesman stated that,
"...getting this test out to the blood banks is our No. 1 priority...." Blood bank directors were
anxiously waiting to start screening blood with the new test until March 2, 1985, the date the first
test kit was approved by the FDA. In the pre-licensure evaluation, sensitivity and specificity of
the test kits were estimated using blood samples from four groups: those with AIDS by CDC
criteria, those with other symptoms and signs of HIV infection, those with various autoimmune
disorders and neoplastic diseases that could give a false-positive test result, and presumably
healthy blood and plasma donors. Numerous complex issues were discussed even before
licensure. Among them were understanding the magnitude of the problem of false-positive test
results, and determining whether test-positive blood donors should be notified. It is now March
2, 1985. The first HIV antibody test kits will arrive in blood banks in the state in a few hours.
Meeting with State Epidemiologist to discuss the appropriate use of this test are the
Commissioner of Health, the medical director of the regional blood bank, and the chief of the
State Drug Abuse Commission. To help in the discussions, the State Epidemiologist turns to prelicensure information regarding the sensitivity and specificity of test kit A. The information
indicates that the sensitivity of test kit A is 95.0% (0.95) and the specificity is 98.0% (0.98).
These and related measures are reviewed below [Show Less]