New rapid HIV test accurate, easy to use

U.S. Army studies it for potential use in military

The long wait for a rapid HIV test may be over early next year, as the manufacturer of one of the more promising tests being researched moves forward with studies at 20 U.S. sites.

The OraQuick HIV-1/2 rapid HIV test, manufactured by Epitope Inc. of Beaverton, OR, was introduced at the XIII International AIDS Conference in Durban, South Africa. It collects oral fluid in 15 seconds, presents test results in 20 minutes or less, requires no needles, is simple to use, and has demonstrated an accuracy of more than 99%.

"Its sensitivity is 100%; its specificity is greater than 99.5%, and it is very easy to use since it works on serum, plasma, or saliva, and it requires no reagents to be added, and all material are included in the kit," said Lt. Hassan Zahwa, MS, manager of the HIV Diagnostic Laboratory at Walter Reed Army Institute of Research in Rockville, MD.

Test still being evaluated

Walter Reed Army Institute has tested a variety of rapid HIV tests, including some that have been as sensitive as OraQuick and others that have had a sensitivity level as low as 66%, Zahwa said.

So far, the OraQuick device has been evaluated in 100 samples. The next step will be to evaluate it in 1,000 samples and then on 12,000 samples. Rapid HIV tests that continue to prove highly accurate at the 12,000-sample level are possible candidates for use by the U.S. Army and in military hospitals, he said. "OraQuick is one of the tests we’re very excited about," he added.

Epitope received approval in April for its investigational device exemption from the Food and Drug Administration (FDA) in Washington, DC, and has begun testing about 7,000 samples as part of the data needed to support an application for FDA approval. The company plans to file a pre-market approval application in January 2001 for HIV-1 and HIV-2 screening using OraQuick.

The test works as easily as over-the-counter pregnancy tests: A person swabs his or her upper and lower outer gum with the flat pad end of the device. Then the device is placed into a vial containing a developer solution. Within 20 minutes, a colored line appears in the control area to show that the test was run properly. If the person is HIV positive, a second line appears in the test area.

Safe and accurate rapid HIV testing needs to be approved quickly by the FDA so AIDS service organizations (ASOs) and others can begin to reach some of the estimated 300,000 Americans who are HIV positive and don’t know it, said Julio Abreu, deputy director of government affairs for AIDS Action of Washington, DC.

"In some cases, more than 25% of people who are tested never come back to get their results," he said, "so if you could give a test result to a person in 10 to 20 minutes, that would really capture the folks who otherwise would be lost."

ASOs could offer the rapid test along with counseling and HIV education in a variety of settings, including needle exchange vans, he said. "Then we’ll begin to make a dent on that 300,000 people who are positive and don’t know it."

Army could use rapid test in the field

The U.S. Army needs FDA-approved rapid HIV tests for two reasons, Zahwa said. First, the test would be used to assess prophylaxis administration in the event a health care worker or other Army person is accidentally exposed to the virus.

"Depending on the result of these tests, the physician can make a decision about administering prophylaxis," he said. "We’ve also thought about using it to diagnose HIV in the field or in foreign countries when our soldiers are exposed and the HIV status of the sources is to be determined."

Second, physicians in military hospitals could use the test to check a pregnant woman’s HIV status. If a pregnant servicewoman had not previously sought prenatal care or had not been tested for HIV, the rapid test could let her doctors know whether they needed to administer quick doses of AZT or nevaripine to reduce her risk of spreading HIV to her baby during the delivery.

Physicians would make the decision of whether to use the test under those circumstances, but the Army could provide them with data and literature supporting the test’s reliability, Zahwa said.

The military will not have as much use for the test in determining the HIV status of enlisted men and women, because that is done routinely every two years by mass screening with FDA-approved ELISA and Western blot tests, he said. However, the HIV test might be used by most civilian HIV testing and treatment clinics, he said.