The low down on rapid testing

What if getting tested for HIV was just as easy as going to the bank? What if it was actually more convenient than renewing your driver’s license? Do you think that you would be more likely to get tested? Rapid testing is suggesting exactly that, a way to make testing for HIV less invasive and less expensive, in hopes of encouraging the act of getting tested.

The testing process

Traditional preliminary HIV tests have used an antibody detection method; they test for antibodies to HIV, not the virus itself. Currently, ELISA is a widespread and often commonly used test. It is inexpensive and highly accurate, but positive results must be confirmed by another process which is called Western blotting(2). The combined accuracy of the ELISA and Western Blot tests is greater than 99%(2). However, the combination of these tests can be expensive, and it may take weeks before an individual is able to obtain their results.

Rapid testing

In recent years the introduction of rapid testing has offered solutions to these problems and other advantages. For example like the ELISA test, a rapid test detect the presence of HIV antibodies, and they too must be treated as a preliminary (positive results need to be confirmed by a Western Blot). But unlike ELISAs, rapid tests are… rapid. People can obtain their results in as little as 20 minutes (2). In fact, the test itself only takes 60 seconds – the remaining 19 plus minutes are invested in pre- and post-test counseling. This means that anyone can go into a clinic and test for HIV without the hassle of having to return weeks later (without rapid testing, results must be determined in a lab away from the point of care).

Now you might be questioning my choice of words, namely “hassle.” Whether the results are positive or negative and regardless of the type of test, you would think that a person getting tested would still want to know their test results. Surprisingly, the Director of the Southern Alberta Clinic in Calgary, Dr. John Gill, said in December 2010 that nearly one third of all people who go in to get tested for HIV never return to receive their results (3)! Sometimes the weeks of waiting can take their toll. With rapid testing, the results are instantaneous, which may alleviate the anxieties around a lengthy wait.

Accessibility

As rapid tests don’t require off site labs, they are much more accessible to less developed countries and higher risk areas of the world. Rapid tests will hopefully make HIV testing more accessible to the developed world too.

With tests like OraQuick, clinics in the United States can test for the HIV virus without even drawing blood, it uses patient saliva and again results are obtained in 20 minutes. This is because the test (like other rapid tests, as mentioned) detects HIV antibodies, which are detectable in saliva.. The United States has also approved a rapid test, called Home Access Express HIV-1, for personal, at home use(2). This test, although extremely accessible, is not-so-rapid as the test sample needs to be mailed to a lab.

Although the sky seems to be the limit when it comes to rapid testing, the first order of contention must be: What is available to us in Canada, and what is the future of rapid testing here?

The Medical Devices Bureau of Health Canada first approved the INSTI HIV rapid test back in 2005(1). In March 2011, researchers at the Provincial Laboratory for Public Health in Edmonton have reported the results of comparative tests between the performance of INSTI HIV and classic HIV test methods. They found that INSTI HIV is just as sensitive as the standard preliminary methods(4).

In other words, the results provided by INSTI HIV rapid tests are just as accurate in detecting HIV anitbodies as the standard tests. In spite of these findings… and further in spite of the fact that they were determined in Alberta, rapid tests are still to this day not available to the general public except in specifically predetermined situations. Officials at Alberta Health Services claim that more confidence in rapid test results needs to be established before options will be made available to Albertans(3).

I think it’s safe to say there is a bright and hopeful future in rapid HIV testing. We can only hope that Alberta is able to realize that future sooner than later. This year ACAA will be holding a conference which will include a presentation by Dr. Ameeta Singh about recent findings on rapid HIV and Syphilis testing in Alberta. For more information or to register for ACAA’s conference click here. To read ACAA’s position statement on rapid testing click here.

Sources:

1. 2007, Canadian AIDS Society,
http://www.cdnaids.ca/web/backgrnd.nsf/pages/cas-gen-0142

2. 2009, THE BODY – The Complete HIV/AIDS Resource, http://www.thebody.com/content/art2497.html#rapid

3. December 1 2010, CBC News, Rapid HIV test urged for Alberta, http://www.cbc.ca/news/canada/edmonton/story/2010/12/01/calgary-alberta-aids-hiv-test-rapid.html

4. March 2011, J Virol Methods, 172(1-2):66 – 71, Lee BE, Plitt S, Preiksaitis JK, Singh AE, Rapid HIV tests in acute care settings in an area of low HIV prevalence in Canada, http://www.ncbi.nlm.nih.gov/pubmed/21192977

This post was written by Cory Waller an AIDS Calgary Awareness Association volunteer blog writers. Cory has a B.Sc in Biochemistry. This blog was originally posted in May 13, 2011 on AIDS Calgary's The A Word