Infectious Disease
HIV antibody/antigen (human immunodeficiency virus) rapid test
Point-of-care HIV tests detect antibodies to HIV-1 and HIV-2, and in fourth-generation formats the p24 antigen, from a small blood or oral-fluid sample taken at or near the patient. They are qualitative screening tests that report a reactive or non-reactive result, not a numerical concentration, and any reactive result is preliminary and must be confirmed by laboratory testing.
Why it is measured
HIV testing supports early diagnosis, linkage to treatment and onward-transmission prevention, and is used in routine screening, antenatal care, sexual-health services and outreach where rapid near-patient results improve the chance that a person receives and acts on their result.
| Typical range | Qualitative result: Non-reactive (negative) is the expected finding in an unaffected adult. Results are read as reactive or non-reactive rather than as a numeric value with units. A reactive result is a preliminary positive that requires confirmatory laboratory testing. Cut-offs, the analytes detected (antibody only versus antigen/antibody) and the diagnostic window vary by method and device; rapid and self-tests typically have a longer window (up to about 90 days) than fourth-generation laboratory assays (about 18 to 45 days). |
|---|---|
| Sample | Finger-prick (capillary) whole blood is most common at the point of care; depending on the device, oral (gingival) fluid, venous whole blood, serum or plasma may also be used. |
| Turnaround | About 1 to 20 minutes at the point of care, depending on device: INSTI reads in roughly 60 seconds, while OraQuick ADVANCE and Determine-type tests are read at around 20 minutes. |
Point of care devices that report it
- OraQuick ADVANCE Rapid HIV-1/2 Antibody Test (OraSure)
- OraQuick In-Home HIV Test (OraSure)
- INSTI HIV-1/HIV-2 Antibody Test (bioLytical Laboratories)
- Determine HIV-1/2 Ag/Ab Combo (Abbott)
- BioSure HIV Self Test (BioSure, UK)
Questions, answered
Does a non-reactive rapid HIV result completely rule out infection?
Not always. A non-reactive result is reassuring but reflects the test's window period, which is the time after exposure before antibodies or antigen become detectable. For rapid and self-tests this window can extend to around 90 days. If exposure was recent, repeat testing at a later date is generally advised. This is general information, not advice for any individual.
What should happen after a reactive point-of-care HIV result?
A reactive rapid result is a preliminary positive only and is not a diagnosis. It must be confirmed with laboratory testing following the recommended diagnostic algorithm before any clinical decisions are made, and the person should be linked to specialist services for confirmation and support.
What is the difference between third- and fourth-generation rapid tests?
Third-generation tests detect HIV antibodies only, whereas fourth-generation tests, such as antigen/antibody combo formats, also detect the p24 antigen, which can appear earlier in infection. Antigen/antibody devices can therefore shorten the detection window, though performance still varies by sample type and device.