Most HIV tests are accurate in the time frame you mentioned, and I'll provide some specifics below. If you have questions ask your doctor, but both antibody and antigen tests are generally reliable in the time frame you mention.
How long after a possible exposure should I wait to get tested for HIV?
Most HIV tests are antibody tests that measure the antibodies your body makes against HIV. It can take some time for the immune system to produce enough antibodies for the antibody test to detect, and this time period can vary from person to person. This time period is commonly referred to as the Ã¢â‚¬Å“window period.Ã¢â‚¬Â Most people will develop detectable antibodies within 2 to 8 weeks (the average is 25 days). Even so, there is a chance that some individuals will take longer to develop detectable antibodies. Therefore, if the initial negative HIV test was conducted within the first 3 months after possible exposure, repeat testing should be considered >3 months after the exposure occurred to account for the possibility of a false-negative result. Ninety-seven percent of persons will develop antibodies in the first 3 months following the time of their infection. In very rare cases, it can take up to 6 months to develop antibodies to HIV.
Another type of test is an RNA test, which detects the HIV virus directly. The time between HIV infection and RNA detection is 9Ã¢â‚¬â€œ11 days. These tests, which are more costly and used less often than antibody tests, are used in some parts of the United States.
For information on HIV testing, you can talk to your health care provider or you can find the location of the HIV testing site nearest to you by visiting the National HIV Testing Resources Web site at http://www.hivtest.org
or call CDC-INFO 24 Hours/Day at 1-800-CDC-INFO (232-4636), 1-888-232-6348 (TTY), in English, en EspaÃƒÂ±ol. Both of these resources are confidential.
If you would like more information or have personal concerns, call CDC-INFO 24 Hours/Day at 1-800-CDC-INFO (232-4636), 1-888-232-6348 (TTY), in English, en EspaÃƒÂ±ol.