What is the OraQuick Rapid HIV-1 Antibody Test, and how is it performed?
The OraQuick Rapid HIV-1 Antibody Test checks for HIV-1, the virus that causes AIDS, in a person’s blood. The test detects antibodies to HIV-1 found in blood specimens obtained by fingerstick or venipuncture. As is true of all HIV screening tests, a reactive test result needs to be confirmed by an additional, more specific test.
When testing a fingerstick specimen, the fingertip is cleaned with alcohol and pricked with a lancet (needle) to get a small drop of blood. The blood is collected with a specimen loop and transferred to a small plastic vial containing a premeasured volume of developing solution, into which the sample is mixed. The testing process is the same for a whole blood specimen obtained by venipuncture. The specimen loop is inserted into the tube of blood after the tube has been inverted to ensure the blood is well mixed. The loop is then inserted into the test vial. Results of the test can be read in as little as 20 minutes.
How well does the test work?
In the clinical studies by the manufacturer (OraSure Technologies, Inc.), the OraQuick test correctly identified 99.6% of people who were infected with HIV-1 (sensitivity) and 100% of people who were not infected with HIV-1 (specificity). The Food and Drug Administration expects clinical laboratories to obtain similar results.
What are the limitations of the test? Does this test always give a correct result?
The limitations of this test are similar to the limitations of other
HIV antibody tests, including
- False-positive results: Although no false-positive results
were found in the clinical trial, statistical analysis of the data
show that a very small number of people who are not infected with HIV-1 will have
reactive test results (that is, tests that show HIV infection). As
the test becomes widely used in outreach settings, false-positive results
may occur. Reactive results should not be considered definitive until
confirmatory testing has been done.
- False-negative results: A small number of people who are infected with HIV-1 will have negative test results.
- Delayed detection of exposure: OraQuick may not detect HIV-1
infection in people who were exposed within 3 months before being tested
(it
can take that long for antibodies to HIV-1 to be detectable in the
blood).
- Follow-up testing: A reactive result is interpreted
as preliminarily positive for HIV-1 infection. Another method should
be used to confirm
the initial test result.
Because of these limitations, all persons taking this test must receive
counseling before being tested and after receiving their test results.
What type of counseling is provided to persons getting a rapid HIV test?
Counseling for rapid HIV tests includes
-
Information about the importance of HIV testing
-
Ways to reduce the risk of becoming infected with HIV
-
Next steps for persons who have a reactive test result
-
Need for additional testing of persons whose rapid test result is negative but who have had a recent exposure to HIV
CDC recently released revised guidelines for HIV counseling
and testing. These guidelines, available at
http://www.cdc.gov/mmwr/indrr_2001.html,
include information about posttest counseling for persons tested
with rapid HIV tests. The counseling includes information about
HIV
testing
and its importance, as well as specific counseling to help
reduce
risks for HIV infection. A very important part of counseling
persons who
have a reactive rapid HIV test result is to make sure they
understand that the test result is preliminary and that further
testing
must be done to confirm the result. Persons who have a negative
rapid
test
result but have had a recent exposure to HIV are counseled
to get another test at least 3 months after the possible exposure
to account
for the
possibility of a false-negative test result. For more information
on rapid testing, go to CDC’s rapid testing Web site
at:
http://www.cdc.gov/hiv/topics/testing/rapid/.
Does this test detect antibodies to HIV-2?
The test is approved to detect antibodies to HIV-1. Data on the test’s
sensitivity to detect antibodies to HIV-2 have not been reviewed, and
the Food and Drug Administration has not approved the test for this
purpose. Because HIV-2 is very rare in the United States, CDC does
not recommend routine screening for HIV-2 at this time.
Are blood donors allowed to be screened by use of the OraQuick test?
No. This test is approved to help diagnose HIV infection, not to screen
blood donors.
I heard the rapid test received a CLIA waiver. What does this mean? CLIA refers to the Clinical Laboratory Improvements Amendments of
1988, which established standards for all laboratory testing to ensure
the accuracy, reliability, and timeliness of test results regardless
of where a test is performed.
The OraQuick Rapid HIV-1 Antibody Test was categorized as a waived
test by the Food and Drug Administration on January 31, 2003. The OraQuick
test is simple to use and accurate. Under the waived category, the
OraQuick rapid test will face less strict federal controls and can
be used at a larger number of clinical and nonclinical testing sites.
This categorization will allow nonclinical testing sites to provide
the test by applying for a CLIA certificate of waiver or agreeing to
work under an organization that has a certificate of waiver. For tests
categorized as waived, less stringent guidelines apply. However, before
offering testing, an organization that has received a certificate of
waiver must have a quality assurance plan and must provide training
to ensure that the manufacturer’s instructions are followed.
For more information on the CLIA waived category and other CLIA categories,
go to: http://www.phppo.cdc.gov/clia/.
What needs to be done before a site is permitted to purchase and use the test?
Any site offering the rapid HIV test is considered a laboratory under
the Clinical Laboratory Improvements Amendments (CLIA) and must meet
certain quality assurance requirements before purchasing OraQuick.
Under CLIA, a laboratory is defined as any facility that performs examinations,
including the OraQuick rapid test, on humans. A facility can be a clinic
or hospital with an on-site lab, a voluntary counseling and testing
site, or an outreach setting. Only staff of clinical laboratories may
use the test. All customers will receive a letter indicating that their
purchase of OraQuick means that they agree to meet these requirements. Any organization or group conducting the OraQuick rapid HIV test must
- Have a CLIA certificate of waiver or be covered under an exception
for multiple sites or public health use (The exceptions involve working
with a main location that has a CLIA certificate of waiver.)
- Ensure that persons administering the test follow the manufacturer’s
test instructions
-
Have a quality assurance plan to ensure that certain requirements,
such as performing testing correctly and providing staff with appropriate
instructional materials, will be met
-
Agree to allow inspections, announced and unannounced, by
the federal Centers for Medicare and Medicaid Services
-
Follow HIV testing requirements or guidelines from the state
health department
How can I obtain a certificate of waiver? The CLIA program is administered by the federal Centers for Medicare
and Medicaid Services. For information on obtaining a certificate of
waiver, go to: http://www.cms.gov/clia/.
What does it mean to have an “adequate quality assurance system”?
An adequate quality assurance system consists of planned activities
to ensure that testing is carried out correctly and that test results
are as accurate and reliable as possible for all persons tested. CDC’s
recommendations for quality assurance systems for rapid HIV testing
-- Quality Assurance Guidelines for Testing
Using the OraQuick® Rapid
HIV-1 Antibody Test -- are available at:
http://www.cdc.gov/hiv/topics/testing/rapid/.
Can waived tests be performed at nonclinical sites?All testing sites, clinical and nonclinical (e.g., mobile vans, health fairs,
community clinics, pharmacies) are subject to applicable state requirements.
Conducting HIV testing by using the OraQuick Rapid HIV-1 Antibody Test, which
is categorized as waived under the Clinical Laboratory Improvements Amendments
(CLIA), will allow nonclinical testing sites to participate in HIV screening
activities.
How much does the test cost?
The manufacturer and the laboratory performing the test determine
the fee for the test.
Reference Kelen GD, Shahan JB, Quinn TC. Emergency department–based
HIV screening and counseling: experience with standard and rapid serologic
testing. Annals of Emergency Medicine 1999; 33:147-155.
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