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As another World AIDS Day is observed on December 1, there are more than 1 million Americans living with HIV/AIDS.

However, an estimated 25 percent of that group doesn't realize they are infected.

Healthcare professionals agree screening is a vital part of prevention, behavior modification, treatment and outcomes. Today, more people with HIV/AIDS are living longer and enjoying a higher quality of life as new medications have turned what was once an automatic death sentence into a much more manageable … albeit still frightening … disease.

The value of testing is so important that the United States Centers for Disease Control and Prevention (CDC) revised their HIV screening recommendations in late September of this year (see box). Although not legally binding, the expectation is that the new recommendations will have a major impact on the volume of testing done and that patients who undergo screening will want quick answers. Rapid tests administered and read at the point of care are a viable and economical option to meet increased demand.

In America, there are a handful of companies that have FDA clearance for rapid tests. Currently only OraSure Technologies (OraQuick® Advance™ Rapid HIV-1/2 Antibody Test) and Trinity Biotech (Uni-Gold™ Recombigen® HIV Test) have received CLIA waivers allowing their tests to be more broadly administered by lesser-trained healthcare workers as a result of the ease of performing the tests and reading results.

A third FDA-approved company, Chembio Diagnostics, Inc., which manufactures two rapid HIV tests, expects a CLIA waiver in the near future. Larry Siebert, president of Chembio, said his company produces two basic tests — the HIV 1/2 Stat-Pak™ Dipstick Assay and the Sure Check® HIV 1/2 Assay — both of which detect antibodies to HIV1 and HIV2, the two major strains of the virus.

The Sure Check test incorporates a patented closed barrel technology that is particularly well-suited for finger-stick whole blood. It allows the tester to draw blood into the barrel, which holds the test strip. Once blood is absorbed, the barrel tip is punched through the buffer vial and placed upright in an enclosed rack. Within 15 minutes, results are ready (with positive readings often visible in a shorter time frame). Much like a home pregnancy test, one pink control line means a negative reading. Two pink lines is a positive reading, and no control line indicates an invalid test. Siebert said the product minimizes a provider's exposure to blood since the test is a single, cNurse Aide Registry losed system.

The HIV 1/2 Stat-Pak uses a more standard cassette system but with the same type of reading for results.

"What's nice about that product is it's very flexible because it uses the same procedure for all types of collection … serum, plasma, venous whole blood or finger stick whole blood," he explained.

Siebert said all the rapid tests available on the United States market have accuracy rates of 99.7 percent or better on whole blood data. If a rapid test returns a negative response, the patient goes home with a clean bill of health. With a positive response, a confirmatory test is required.

"In the United States, we're still sending out preliminary positive results to a lab for a confirmatory test. Overseas, in sub-Saharan Africa for example, they don't have the facilities or the time to do that so they use a combination of tests to not only screen but confirm," Siebert explained, adding that the tests are sometimes in sequence (a second is run only if the first screening test result is positive … a so-called serial algorithm) and at other times in parallel (two tests as screens … a so-called parallel algorithm). Siebert noted his company's product is used as the confirmatory test in the serial algorithm in Uganda and is one of the screening tests in the parallel algorithm being used in Nigeria.

Siebert said that while there are only about 1 million cases of HIV/AIDS in America, there are approximately 39 million additional cases worldwide, and the vast majority of those with the virus globally are unaware of their condition.

"Why would anybody take an HIV test?" Siebert questioned of the mentality just a few years ago in countries heavily hit by AIDS. "If it happened to be positive, they were just going to find out they were going to die. Now, through PEPFAR (President's Emergency Plan for AIDS Relief), it looks like they have a much better chance of getting treated," he said.

To meet the goal of treating 2 million people infected with AIDS, Siebert and other colleagues estimate it will take about 200 million rapid tests.

"The only way to find out whom to treat is to test," he pointed out.

Siebert noted some countries with large populations such as Ethiopia, Nigeria and South Africa have started to implement wide-scale rapid testing. Brazil, Thailand and Uganda are thee other examples he cited as aggressively testing in an effort to curb the spread of HIV/AIDS.

"We've shipped about 700,000 tests to Nigeria in the last six months," he said.

Whether at home or abroad, Siebert stressed information is power and having an accurate diagnosis is the first step in taking advantage of today's improved medical treatment options.


December 2006

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