Quick Facts
- Sample: Blood
- Fasting: No fasting is required. Stop biotin consumption at least 72 hours prior to the collection.
- Turnaround: 1-2 business days. May take longer based on weather, holiday or lab delays.
What This Test Measures
The HIV-1/2 Preliminary Blood Test (4th generation) checks your blood for two things: antibodies to HIV-1 and HIV-2, and the p24 antigen, a viral protein that makes up the majority of the HIV viral core (capsid). Results are reported as a screening result with a final interpretation.
Testing for both antibodies and antigen allows this test to detect a significantly higher number of early infections than previous generations of HIV screening. If the initial screen is positive, supplemental testing is included at no extra cost. This begins with repeat runs of the screen, followed by an HIV Multispot test, and then a Qualitative RNA test if the Multispot result is negative or indeterminate.
Benefits
- Screens for both HIV antibodies and p24 antigen in one blood sample.
- Detects a significantly higher number of early infections than earlier screening generations.
- Includes supplemental testing at no extra cost after a positive screen.
- Requires no fasting, with results typically in 1-2 business days.
Who Is This Test For?
- Adults between the ages of 18 and 65 getting tested at least once.
- Men who have sex with men.
- People with new or multiple sex partners.
- People who have had unprotected sex with someone at high risk of HIV.
- People who share or have shared injection drug needles.
- People concerned about a possible STI exposure or who have had another STI.
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What does the HIV-1/2 Preliminary Blood Test (4th generation) measure?
This test screens a blood sample for HIV-1 and HIV-2 by looking for two things: antibodies to the viruses and the p24 antigen, a protein specific to HIV. It may help a healthcare provider evaluate whether HIV is present, but it does not diagnose a condition on its own and is not a complete evaluation of your health. Results are reported as a screening result with a final interpretation.
2. Who should consider this test, and how often should I be tested?
You may consider this test as routine HIV screening, and the source recommends that adults between the ages of 18 and 65 be tested at least once. It may also suit men who have sex with men, people with new or multiple sex partners, people who have had unprotected sex with someone at high risk of HIV, and people who share or have shared injection drug needles. If you are concerned about a possible STI exposure, have symptoms of an STI, have had another STI since your last test, or have hepatitis or tuberculosis (TB), this test may also be a fit. Beyond the one-time recommendation, testing frequency should be as directed by your healthcare provider based on your individual situation. This test does not replace medical evaluation.
3. Do I need to prepare for this test?
No fasting is required. Stop biotin consumption at least 72 hours prior to the collection.
4. How quickly will I get results?
Results are typically available in 1-2 business days. This may take longer based on weather, holiday, or lab delays.
5. How do I interpret my results?
The meaning of your result depends on the specific antibodies and antigen tested and on your clinical context, including timing since a possible exposure, symptoms, medical history, and other laboratory results. Antibodies typically develop several weeks after exposure, so testing too soon may produce a negative result even if the virus is present. A single result should not be treated as a final conclusion.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
6. What happens if my initial screen is positive?
If the initial screen is positive, supplemental testing is included at no extra cost. This begins with repeat runs of the screen, followed by an HIV Multispot test that differentiates antibodies to HIV-1 and HIV-2. If the Multispot result is negative or indeterminate, a Qualitative RNA test follows.
7. What should I do if HIV is detected?
Review your results with a qualified healthcare provider, who can advise whether further evaluation is appropriate. An abnormal result alone does not provide a complete clinical conclusion.
Pre-test preparation
No fasting is required. Stop biotin consumption at least 72 hours prior to the collection.
