Why do you do blood testing rather than an oral swab?

We use antigen/antibody combination tests to test for HIV, which can:

• Detect acute HIV infection before seroconversion (the process by which the body develops detectable antibodies in the blood)
• Provide a positive result as soon as 14-16 days after infection
• Offer sensitivity of 99.76% to 100% and specificity ranging from 99.50% to 100%

While oral swab tests test work within minutes, they cannot detect acute HIV infection prior to seroconversion, they have a clinical sensitivity of only 86%, and they may not become reactive until several weeks after exposure.