ROCKVILLE, MarylandA quick HIV-1 diagnostic test with high specificity
and sensitivity has received conditional approval by the US Food and Drug
Administration (FDA) for use in detecting antibodies to the most common form
of the virus found in the United States.
In approving the OraQuick Rapid HIV-1 Antibody Test (OraSure
Technologies), the agency restricted its sales to the nearly 40,000 labs
approved by the FDA under CLIA, the Clinical Laboratory Improvements
Amendments of 1988. The FDA also specifically stated that the antibody test
is not approved for use to screen blood or tissue donors.
OraQuick is classified by the FDA as a test of moderate complexity. CLIA
requires that new diagnostic tests be categorized as either moderate or high
complexity and their administration restricted to CLIA-certified laboratory
technicians or medical staff at CLIA-approved laboratories. However, OraSure
could seek a waiver for use of the test under less stringent conditions, and
Health and Human Services Secretary Tommy G. Thompson pleaded with the
company to do so.
"If the FDA finds that the company’s data proves that the OraQuick test is
both easy and safe to use, it can get a CLIA waiver. Then the test could be
given in many more health care settings, perhaps even administered by social
workers in HIV counseling centers," Mr. Thompson said in announcing the FDA’s
approval. "But the process can’t begin until OraSure applies for the waiver,
so I ask them to please apply now!" The company agreed readily. "We
absolutely plan to submit for a CLIA waiver," said OraSure spokesman William
HIV diagnosis in the United States currently involves screening with an
enzyme immunoassay (EIA) and confirmation of repeatedly reactive EIAs with
the Western blot test. Obtaining results from these testing procedures
typically takes 2 days to 2 weeks.
The OraQuick test, however, is a single-use, qualitative immunoassay that
can detect HIV-1 antibodies in finger-stick whole blood samples. A blood
sample is mixed in a vial with a developing solution, and the test device,
which resembles a dipstick, is inserted into it.
The test device contains synthetic peptides representing the HIV envelope.
If the blood sample contains HIV-1 antibodies, their presence is revealed in
as little at 20 minutes by two reddish-purple lines that appear in a small
window on the test device. A positive result indicates a preliminary
diagnosis of HIV infection that must be confirmed.