The time between infection and when a test can deteet infection is called the 'window period.' Because there are two ways to test for HIV - antibody testing and RNA testing, there are two answers to this question.
Antibody Tests: The Most Common, including all rapid tests
These tests look for antibodies to HIV, not the virus itself. It takes about 1 month (sometimes up to 3 months) after infection for the body to produce enough antibodies to show up on a test.
The Window Period for Antibody Tests |
| Most people develop detectable antibodies within 2-8 weeks. |
| 25 days is the average time it takes to develop detectable antibodies. |
| 97% of people develop detectable antibodies within 3 months. |
| In very rare cases, it can take up to 6 months to develop antibodies. |
RNA Tests: The Lastest & Greatest
Unlike antibody tests, RNA tests for the presence of the virus itself. They look for HIV's genetic material -- its RNA, which can be detected much sooner than antibodies. RNA tests are done from blood samples and it usually takes two weeks for the lab to process.
The Window Period for RNA Tests |
| The time between HIV infection and RNA detection is 9–11 days. |
RNA tests, which are more costly and used less often than antibody tests, are used in some parts of the United States. Happily, they are offered here in San Francisco.
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