Which HIV Tests Are the Most Accurate?

Study shows that some tests fall short in early infection

A positive reading (two bars) on an OraQuick ADVANCE in-home HIV test.

Orasure Technologies

As the United States aims to increase early diagnosis and treatment of people with HIV, a greater focus has been placed on determining the accuracy of HIV tests in real-world settings—not only to minimize the number of false positive or negative test results but to better identify people during the early (acute) stages of infection when the risk of transmission is especially high.

In order to do this, researchers from the University of California, San Francisco (UCSF) conducted a review of over 21,000 HIV tests performed between the years 2003 and 2008 in some of the city's high prevalence populations.

Of four types of tests used during this period—from first generation antibody tests to rapid oral tests—761 people were diagnosed with HIV (3.6 percent prevalence), while 58 were identified during acute infection.

The study also aimed to compare the accuracy of newer testing assays—including 4th generation antigen/antibody tests—by retesting the blood from the 58 people previously diagnosed with acute HIV infection.

The accuracy was measured both in terms of sensitivity (the percentage of tests that are correctly positive) and specificity (the percentage of tests that are correctly negative).

Test TypeNameSensitivity from 21,234 testsSpecificity from 21,234 testsSensitivity for acute infection from 58 tests
1st generation antibody test (blood)Vironostika HIV-1 Microelisa92.3%100%0%
3rd generation antibody test (blood)Genetic Systems HIV-1/296.2%100%34.5%
3rd generation rapid antibody test (blood)OraQuick Advance91.9%100%5.2%
3rd generation rapid antibody test (saliva)OraQuick Advance86.6%99.9%--
3rd generation rapid antibody test (blood)Uni-gold Recombigen----25.9%
3rd generation rapid antibody test (blood)Multispot HIV 1/2----19.0%
3rd generation rapid antibody test (blood)Clearview Stat Pak----5.2%
4th generation rapid combination antigen/antibody test, (blood)Determine HIV 1/2 Ag/Ab Combo----54.4%
4th generation lab-based combination antigen/antibody test (lab)ARCHITECT HIV Ag/Ab Combo----87.3%

What the Findings Tell Us

From the point of view of specificity, the figures confirmed that the incidence of false positives remains extremely low, even with the earlier generation tests.

By contrast, the rate of false negatives varied considerably, with the saliva-based OraQuick Advance rapid test performing the worst, with just over one in 15 people receiving a false negative result.

The figure only worsened when retesting bloods from the acute stage infections. Of the 58 samples tested, the 3rd generation rapid tests achieved a sensitivity of only 5.2 percent to 25.9 percent, meaning that the majority of such infections would be missed using these rapid, antibody-based tests.

Even the 4th generation Determine rapid antigen/antibody test was able to identify only half of the acute infections despite having an estimated sensitivity of 96.6 percent and specificity of 100 percent. According to the UCSF researchers, the Determine worked best during acute infection when the patient's viral load was over 500,000.

Not surprisingly, the lab-based ARCHITECT combination antigen/antibody test performed best. With an estimated specificity of 99.1 percent and a specificity of 100 percent, the tests were able to identify nearly 90 percent of acute infections.

Making an Informed Choice

In terms of testing selection and performance, the following conclusions can be reasonably drawn:

  • Commercial, over-the-counter HIV tests perform least well overall, not only in terms of detecting acute infection but in returning a false negative rate of 7 percent.  
  • Combination HIV antigen/antibody tests are far more accurate than traditional antibody-based assays, particularly during the acute stage of infection. Lab-based tests still outperform at-site, point-of-care HIV tests, most especially in cases of recent HIV exposure.

    With that being said, high levels of sensitivity are only part of the reason why certain tests are preferred over others. 

    For example, a significant number of people fail to return for their results after testing. The ability to return a result within 20- to 30 minutes makes rapid testing the ideal choice for most people (and increases the likelihood that they'll be linked to care). 

    Similarly, people with confidentiality concerns or fears about HIV stigma may be better served by taking an in-home rapid test. While there remains little data as to the number of people linked to care following a positive result, it is presumed that the tests will at least provide an entry point for those who might otherwise avoid testing clinics.

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