HIV Testing

Why is a HIV Test done?

  • HIV testing is done to confirm the diagnosis in those who are newly infected, to identify previously unrecognized infections, and to relieve the minds of those who are not infected.
  • It is important for pregnant women to be tested because medications are very effective in reducing transmission of HIV from mother to baby.


  • HIV testing is usually a two-step process.
  1. The first step is to test for antibodies in blood or saliva.
  2. If the test is positive, a second test called a Western blot is done to ensure that the first result was correct.
  3. If both tests (antibody and Western blot) are positive, the chances are >99% that the patient is infected with HIV.
  • HIV antibody tests may miss some infections, resulting in false-negative tests. This often occurs soon after infection when antibodies are just starting to form and are at a level too low to be detected.


Antibody Tests: The most common HIV tests look for HIV antibodies in your body, rather than looking for HIV itself:

– ELISA tests use blood, oral fluid, or urine to detect HIV antibodies. Results for these tests can take up to two days.

– Rapid HIV antibody tests also use blood, oral fluid, or urine to detect HIV antibodies. Results for these tests can take 10–20 minutes.

– If you get a positive result from either of these tests, you will need to take another test, called a Western blot test, to confirm that result. This is the gold standard to confirm the diagnosis of HIV infection.

Antigen Tests

These tests are not as common as antibody tests, but they can be used to diagnose HIV infection earlier—from 1-3 weeks after you are first infected with HIV. Antigen tests require a blood sample. The HIV DUO (which tests for antibodies to HIV 1 & 2 and the p24 antigen) test results are accurate and results are available on the same day.

PCR Test (Polymerase chain reaction test)

This test detects the genetic material of HIV itself, and can identify HIV in the blood within 2-3 weeks of infection.

PCR tests are also used to measure viral loads for people who are HIV-positive.

How often should you take an HIV test? Tat depends!

The CDC recommends that HIV screening be a part of routine checkup for all patients aged 13-64. In other words, you should have an HIV test during a medical check-up—just like you have a blood test or a urine test to be sure you are healthy. Many labs include the test in the annual health checkup plans.

In spite of that recommendation, however, most people are tested on the basis of their risk factors for getting HIV. You should get tested for HIV every at least every year if you:

– Share needles/syringes or other equipment (“works”) for injecting drugs

– Have a history of sexually transmitted diseases (STDs)

– Have had unprotected sex (vaginal, anal, or oral) with multiple or anonymous partners. Or if you have had had unprotected sex with a partner who did not know their own HIV status.

Some doctors recommend testing every 3-6 months if you have certain risk factors, including injection drug use and/or unprotected sex with others who engage in high-risk behaviors.

If you or your partner plan to become pregnant, getting an HIV test is very important. All women who are pregnant should be tested during the first trimester and the third trimester of pregnancy.


HIV test results fall under the same privacy rules as all of your medical information. Information about your HIV test cannot be released without your permission.

If you have concerns regarding who can have access to your tests results, it is important to ask your pathology laboratory, about their privacy policies and who, they are required to report a positive result to.


Studies have proven that both conventional and rapid HIV tests are highly accurate when they show an HIV-positive result.

But a negative result may not always be accurate. It depends on when you might have been exposed to HIV and when you took the test.

It takes time for sero conversion to occur. This is when your body begins to produce the antibodies an HIV test is looking for—anywhere from 2 weeks to 6 months after infection. So if you have an HIV test with a negative result within 3 months of your last possible exposure to HIV, the CDC recommends that you be retested 3 months after that first screening test.

A negative result is only accurate if you have had any risks for HIV infection in the last 6 months—and a negative result is only good for past exposure. If you get a negative test result, but continue to engage in high-risk behaviors, you are still at risk for HIV infection


If your initial HIV test comes back positive, you will automatically be offered a confirmatory test. If the confirmatory test is also positive, you will be diagnosed as “HIV-positive.”

You will be referred to a medical professional for follow-up treatment.


If you are diagnosed with HIV, you should do the following things—even if you don’t feel sick:

Find a doctor who has experience treating HIV.

Get screened for other sexually transmitted diseases (STDs) and for TB (tuberculosis). Undetected co-infections, such as STDs and TB, can cause serious health complications—and having HIV makes you more susceptible to those  conditions.

Maintain a healthy lifestyle. This is crucial for success in treating HIV. Smoking, drinking too much, or taking illegal drugs can weaken your immune system, allowing the virus to replicate and grow.

Safer sex practices are very important. Condoms are very effective in preventing HIV transmission when used correctly and consistently.

Tell your partner(s) about your HIV status before you have any type of sexual contact (vaginal, anal, or oral) and don’t share needles or syringes.

Where can you find more information about HIV testing?

The National HIV and STD Testing Resource site ( contains answers to frequently asked questions.

The CDC web site is also a good source of information: This site also contains information on how to order free HIV/AIDS publications.