Hidden Aids

PREGNANT WOMEN WHO HARBOR THE AIDS VIRUS have a 30% chance of passing the infection on to their unborn children. But conventional tests, which detect the presence of antibodies to the virus, cannot determine which babies are infected and thus need immediate treatment. The ambiguity occurs because the mother's own antibodies cross the placenta, causing the newborn to test positive even if it is not infected.

Now scientists at UCLA believe they have found a solution. In their study, published in the New England Journal of Medicine, they used a new test that separates the maternal antibodies from infant blood samples. No longer camouflaged, the AIDS virus was easy to detect.