Q&A: Are Oral HIV Tests Reliable ?

Q: I recently had the oral swab HIV test done. It came back negative, but I’m still worried about whether or not to take a blood test, too – I’ve heard that these oral swab tests can often give false results and may not be as conclusive as a traditional blood screening. The swab test just seemed too fast and easy! Am I worrying for no reason?

Many of the HIV tests that we use do not directly detect the virus, but actually detect the presence of antibodies to the virus. Antibodies circulate in the blood but are also released into the saliva. The oral tests allow for rapid screening, client education and counseling and referrals for confirmatory tests when necessary.

Yes, the oral test can be incorrect – but so can blood tests. People can test negative when they’re actually positive and vice versa. This seldom happens and both the oral test and the blood tests are highly accurate. You can always request a blood test if you don’t feel comfortable with the results. There is a very low chance that two tests can both be wrong. Individuals who test positive on the oral test are referred to have a blood test for confirmation.

The important concept here is that oral tests and the major blood tests, the Western Blot test and ELISA test, detect antibodies to HIV. The problem is that once a person is infected with HIV, it takes the body several weeks to produce HIV antibodies. During this window, these tests could be negative or “indeterminant” when the person is actually inefcted. One option is to repeat the test in a couple months. If there is indeed an infection, this would allow more time for levels of antibodies to rise enough to be detected with the test.