MAN WITH AIDS TESTS NEGATIVE FOR HIV; NEW SCREENING PLAN NEARS\APPROVAL.

Byline: The New York Times

Federal health officials Thursday reported a rare case of an individual with AIDS who persistently tested negative for the AIDS virus. The man, who lives in Utah, was a longtime blood plasma donor, but an investigation found no evidence that his plasma had infected anyone, the Centers for Disease Control and Prevention said in its weekly report.

The report comes at a time when the Food and Drug Administration is about to license a new test for HIV, the virus that causes AIDS, that differs substantially from the standard one that has been used to screen all blood donations since 1985. If the new test had been available earlier, it probably would have detected the man's HIV infection, said officials with the centers.

But there is a sharp conflict among health officials and professionals over the value of the new test because it would screen out only a tiny number of additional contaminated blood products, yet would add millions of dollars to testing costs.

In August, the FDA recommended that blood banks supplement the standard test with the new test within 90 days of its licensing. The new test detects the p24 antigen, or protein, in HIV. The standard test detects antibodies that the immune system produces in response to HIV infection and has been enormously successful in preventing transfusion-associated AIDS.

About one in 450,000 donations is contaminated with HIV and still escapes detection, however, because of the so-called window period. It is the interval from the time an individual becomes infected with HIV until the immune system produces the antibodies that are detected by the standard test. The average window period is now 25 days.

On average, the new test will detect HIV about six days before the standard test does and will detect four to six contaminated blood donations annually that would not be identified by other tests.

Because blood is broken down into component materials, the new test would be expected to remove seven to 11 infectious components each year that would otherwise be available for transfusion, the centers said in guidelines that it expects to publish in a few days.

Controversy has swirled around the FDA's decision because the federal agency in June rejected its own advisory committee's recommendation not to use the p24 antigen test for screening blood. Such a rejection is highly unusual.