Testing for HIV

I may have been exposed to HIV. What should I do?

Get tested. The only way to know if you're infected with the virus is to get an HIV test.

Although some people newly infected with HIV may have flu-like symptoms, such as fever, sore throat, and rash, HIV can't be diagnosed by symptoms. Getting tested is the only way to know if you're infected with HIV.

What is the most common HIV test?

The most common HIV test is the HIV antibody test. The HIV antibody test checks for HIV antibodies in a person's blood, urine, or fluids from the mouth.

When a person becomes infected with HIV, the body begins to produce antibodies to HIV. Generally it takes about 3 months to produce enough antibodies to be detected by an HIV antibody test. (For some people, it can take up to 6 months.) The time period between infection and the appearance of detectable HIV antibodies is called the window period. Because HIV antibodies are not yet dectable, the HIV antibody test is not useful during the window period.

What HIV test is used during the window period?

The plasma HIV RNA test (also called a viral load test) can detect HIV in a person's blood within 9 days of infection, before the body develops detectable HIV antibodies. The plasma HIV RNA test is recommended when recent infection is very likely -- for example, immediately after a person has had unprotected sex with a partner infected with HIV, and especially if the person also has flu-like symptoms.

Detecting HIV at the earliest stage of infection lets people take steps right away to prevent HIV transmission. (See the Preventing HIV Transmission fact sheet.) This is important because immediately after infection the amount of HIV in the body is very high, increasing the risk of HIV transmission. Starting treatment at this earliest stage of infection may also be considered.

What does it mean to test HIV positive?

To be diagnosed with HIV, a person must have positive results from two HIV tests. The first test may be either an HIV antibody test (using blood, urine, or fluids from the mouth) or a plasma HIV RNA test (using blood). The second test (always using blood) must be a Western blot test. The Western blot test confirms that a person has HIV.

How long does it take to get HIV test results?

Results of the first antibody test are generally available within a few days. (Rapid HIV antibody tests can produce results within an hour.) Results of the plasma HIV RNA test and Western blot are available in a few days to a few weeks.

If I test HIV positive now, will I always test HIV positive?

Yes. There's no cure for HIV. Because you will always be infected with the virus, you will always test HIV positive. However, treatment with anti-HIV medications can keep you healthy and protect you from AIDS-related illnesses.

If a pregnant woman tests positive for HIV, will her baby be born with HIV?

In the United States and Europe, fewer than 2 babies in 100 born to mothers infected with HIV are infected with the virus. This is because most mothers infected with HIV and their babies receive anti-HIV medications to prevent mother-to-child transmission of HIV. (For more information, see the HIV and Pregnancy fact sheet series.)

Where can I find information on HIV testing locations?

Many hospitals, medical clinics, and community organizations offer HIV testing. To find an HIV testing site near you, contact AIDSinfo for the number of your state AIDS hotline or visit www.hivtest.org/.

For More Information

Contact an AIDSinfo health information specialist at 1–800–448–0440 or visit http://aidsinfo.nih.gov. See your health care provider for medical advice.

This information is based on the U.S. Department of Health and Human Services' Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents (available at http://aidsinfo.nih.gov/Guidelines/).