HIV

Q: How accurate is the rapid oral HIV test?

The rapid oral HIV test detects antibodies made by the immune system in response to HIV infection, just like the standard blood antibody test. The rapid oral test, however, detects these antibodies in oral fluid, and doesn't require a blood sample.

The rapid oral HIV test is quite accurate (similar to the standard blood antibody test) for persons with chronic, or longstanding, HIV infection, but it is not as accurate for people with new or recent HIV infection. Like any antibody test for HIV, the rapid oral HIV test is not reliable during the "window period" (lasting several weeks to months) between the time a person is infected and the time the body has made enough antibodies for the test to detect. During this window period, someone who is infected might test negative for antibodies (a false-negative result). The "window period" for the rapid oral test is longer than it is for some HIV blood tests, meaning that for someone with acute or new HIV infection certain blood tests can detect HIV earlier than the oral rapid tests.

It also is possible to have false-positive results (a person may have a positive rapid oral HIV test result but not actually be infected with HIV). That's why anyone who has a positive result with a rapid oral HIV test must have a more specific "confirmatory" blood test before a diagnosis of HIV infection can be made.