What is the OraQuick Rapid HIV-1 Antibody Test and how is it performed?
The OraQuick Rapid HIV-1 Antibody Test (OraQuick) is a screening test for HIV-1, the virus that causes AIDS. It is a single-use qualitative immunoassay that detects antibodies to HIV-1 in a fingerstick sample of blood. As with all HIV screening tests, a reactive test result needs to be confirmed by an additional, more specific test.
To perform the test, the fingertip is cleaned with alcohol and pricked with a lancet to get a small drop of blood. The blood is collected with a specimen loop and transferred to a vial, where it is mixed with a developing solution. The test device is then inserted into the 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, OraQuick 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). FDA 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 Positives - although none were found in the clinical trial, a statistical analysis of the data indicates that a very small number of people who are not infected with HIV-1 will have reactive test results. As the test is used in broad outreach settings it is expected that false positives may be seen and therefore reactive results should not be considered definitive until confirmatory testing has been completed.
- False Negatives - a small number of people who are infected with HIV-1 will have negative test results.
- Delayed detection of exposure -- this test will not detect HIV-1 infection in people who were exposed within about three months prior to taking the test (since it can take that long for detectable antibodies to HIV-1 to appear in the blood).
- Follow-up testing - a reactive result is interpreted as preliminarily positive for HIV- 1 infection. Individuals with reactive test results should have follow-up testing using another method to confirm the initial test result.
For these reasons, all individuals taking this test must receive counseling both before being tested and after receiving their test results.
What type of counseling is done for rapid HIV tests?
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 people who have a reactive test result
- Need for additional testing in people who have had a recent exposure to HIV
For more information about HIV counseling, see CDC¿s Divisions of HIV/AIDS Prevention website (http://www.cdc.gov/hiv/dhap.htm).
Does this test detect antibodies to HIV-2?
This test is approved to detect antibodies to HIV-1. Because HIV-2 is very rare in the United States, the CDC does not recommend routine screening for HIV-2 at this time.
Are blood donors allowed to be screened using the OraQuick test?
No. This test is approved to help diagnose HIV infection, not to screen blood donors.
Who is permitted to purchase and use the test?
Only clinical laboratories that meet certain quality assurance requirements may purchase OraQuick. In addition, only agents of clinical laboratories may use the test. An agent of the clinical laboratory is someone who works for the laboratory whether it is high complexity, moderate complexity, or waived. All customers will receive a letter indicating that through their purchase, they agree to meet these requirements.
Quality assurance requirements include:
- planned systematic activities to assure that requirements for quality will be met, and
- assurance that operators will receive and use the instructional materials.
What constitutes a ¿clinical laboratory?
A clinical laboratory is a facility for the examination of materials taken from the human body, to help diagnose, prevent, or treat a human disease or condition. CLIA requires all entities that perform even one test, including waived tests on ... "materials derived from the human body" to meet certain Federal requirements. If an entity performs tests for these purposes, it is considered under CLIA to be a laboratory.
For CLIA¿s definition of a clinical laboratory, see 493.257 FR 7139, Section 493.2 Definitions.
What constitutes an ¿adequate quality assurance system?
An adequate quality assurance system consists of planned and systematic activities to ensure that a laboratory will meet certain requirements for quality. CDC is currently developing recommendations for quality assurance systems for rapid HIV tests. These recommendations should be available soon and are being developed in a manner to ensure that both quality and broader access to testing will be possible.
OraQuick was originally approved as a moderate complexity test under CLIA. What is different now that the test is waived?
As a moderate complexity test, OraQuick could only be purchased and used by laboratories that were certified to conduct moderate complexity laboratory testing. Laboratories with this level of certification must meet CLIA requirements for personnel, training, and inspections, among others.
In contrast, laboratories performing only waived tests, must only meet the following requirements under CLIA:
- Enroll in the CLIA program;
- Pay a biennial fee to obtain a Certificate of Waiver; and
- Follow manufacturers' test instructions.
How can I obtain a Certificate of Waiver?
The CLIA program is administered by the Centers for Medicare and Medicaid Services (CMS). Information on obtaining a Certificate of Waiver can be found on the CMS CLIA Program website (http://www.cms.gov/clia/cliaapp.asp).
How much does the test cost?
The manufacturer and the laboratory performing the test determine the fee for the test.