Your Essential Guide to HIV Testing and Diagnosis

Rapid HIV tests resting in their holders
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When referring to the diagnostic tests used for HIV, we often take that to mean the ubiquitous HIV test—or the test used to confirm whether or not an infection has taken place.

In fact, there are a number of different tests that are used in the detection, treatment, and management of HIV, all of which can tell us

  • whether we are HIV-negative or HIV-positive;
  • which drugs would be most effective for us as individuals;
  • how effectively we are responding to therapy:
  • if any drug side effects are developing, and;
  • whether we're developing resistance to our HIV drugs.

The importance of HIV testing has arguably never been greater. Today, it is estimated that of 1.2 million Americans living with HIV, a staggering 20 to 25 percent remain undiagnosed, while fewer than one in four are able to maintain an undetectable viral load vital to treatment success.

It is important, therefore, to understand what each of the tests entails, what the results actually mean, and how they apply to you as an individual, whether you are HIV-positive or not.

1. Who Should Get an HIV Test (and When)?

It used to be that HIV testing was recommended only for those identified as being "at risk." In April 2013, all of that changed when the U.S. Preventive Services Task Force issued recommendations that all persons between the ages of 15 and 65 be screened for HIV as part of a routine doctor visit.

2. What Is the Preferred Method for HIV Testing in the U.S.?

On June 27, 2014, the Centers for Disease Control and Prevention (CDC) recommended a new strategy for HIV testing using 4th generation combination assays able to detect HIV infection up to four weeks earlier than current antibody-based tests. Rather than relying solely on the detection of HIV antibodies (i.e., the defensive proteins produced in response to HIV), these combination assays are able to detect both antibodies and antigens.

3. What Are Your HIV Testing Options?

Today, there a number of HIV testing options ranging from so-called "point-of-care" tests performed at a health facility to in-home rapid tests that provide you results in as little as 20 minutes. Learn how each of these tests are performed, what their limitations are, and how they may be (or may not be) appropriate for you as an individual.

4. How Confidential Is HIV Testing?

Breach of confidentiality is often cited as the most salient reason for avoiding HIV testing among low-income, at-risk Americans. Despite laws designed to protect an individual’s health information, there still remains confusion as to where medical privacy begins and ends. Learn what your legal rights are and what you can do if you find that your privacy has been breached.

5. How Often Do False Positives and False Negatives Occur?

Although the rate of false positive and false negative HIV test results is low, they do sometimes occur. Learn why these anomalies occur, which tests are more prone to inaccurate results, and what you should know to ensure you get the most accurate results possible.

6. How Accurate Are In-Home HIV Tests?

According to the FDA, the OraQuick Rapid In-Home Test is not only safe and easy-to-use but offers a sensitivity and specificity of roughly 95 percent—slightly less than the 99.3 percent and 99.8 percent seen with clinic-based tests. However, unlike point-of-care tests, the in-home version is known to have a false negative rate of around 7 percent, meaning that one out of every 12 tests will deliver an incorrect "all clear" sign.

7. What Does CD4 Count and Viral Load Mean?

In their most basic terms, the CD4 count measures the strength of a person’s immune function, while the viral load measures the amount of virus in a person’s body. Learn what these values actually they tell us, how they relate to each other, and how proper monitoring can prevent the premature "virologic failure" of individuals on HIV therapy.

8. How Often Should You Get Your CD4 and Viral Load Tested?

With the increased efficacy of modern antiretroviral therapy (ART), the emphasis should no longer be placed on using CD4 counts as the measure of ART success. According to guidelines issued by the U.S. Department of Health and Human Services (DHHS) on May 1, 2014, viral loads should alone be used to determine this, while CD4 counts may in some cases be considered optional.

9. What Do Your Routine Blood Tests Mean?

When is a person is diagnosed with HIV, regular blood tests are performed as a course of therapy. These tests can be predictive of a developing infection or measure the person's response to the drugs themselves—detecting or even preventing side effects that sometimes occur. Learn what these tests mean and how, by understanding a few key values, you can better participate in the on-going management of your HIV.

10. What Are Genetic Resistance and Tropism Tests?

There are tests frequently used to determine whether a person is a candidate for a certain type drug therapy and/or what types of drug resistance have developed in the person’s so-called "viral pool." By performing these tests, doctors can effectively tailor the therapy to the individual, ensuring treatment durability and optimal treatment results.