Deciding If and When to Be Tested
January 22, 2007
The following are behaviors that increase your chances of getting HIV. If you answer yes to any of them, you should definitely get an HIV test. If you continue with any of these behaviors, you should be tested every year. Talk to a health care provider about an HIV testing schedule that is right for you.
If you have had sex with someone whose history of sex partners and/or drug use is unknown to you or if you or your partner has had many sex partners, then you have more of a chance of being infected with HIV. Both you and your new partner should get tested for HIV, and learn the results, before having sex for the first time.
For women who plan to become pregnant, testing is even more important. If a woman is infected with HIV, medical care and certain drugs given during pregnancy can lower the chance of passing HIV to her baby. All women who are pregnant should be tested during each pregnancy.
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 "window period." 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 9–11 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 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 Español. 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 Español.
This article was provided by U.S. Centers for Disease Control and Prevention. Visit the CDC's website to find out more about their activities, publications and services.