Research presented Monday at the first national conference on AIDS prevention used the blood tests to show that new infections are continuing at a steady rate, as researchers previously estimated.
Though standard blood tests show whether a person is infected with HIV, the virus that causes AIDS, they do not tell if infection occurred recently or a long time ago. That has made it hard for scientists to say with certainty from year-to-year whether new infections are increasing, declining or staying the same.
The new test, developed by the Centers for Disease Control and Prevention along with other organizations, can identify infections as four-to-six months old using the same blood samples as the standard tests.
"It's the first time we have had timely HIV incidence data on a broad scale," said Dr. Robert Janssen, one of the CDC AIDS researchers who helped develop the test.
It's still too early to tell if the test will have significant medical impacts by catching early infections, Janssen said. But he said it should help newly infected patients identify sexual partners who either may have infected them or contracted the virus from the patient after he was infected.
The CDC has been using the new blood test for only about the last two months, Janssen said.
Using the new blood test to study 96,000 people visiting STD clinics in six cities between 1991 and 1997, the CDC found "no apparent increases or decreases in the rate of new infections" in either homosexuals or heterosexuals, said Dr. Hillard Weinstock, a CDC researcher.
Written By Russ Bynum