Silent Aids A troubling finding

Researchers have known for some time that people may harbor the AIDS virus without showing symptoms or even producing telltale antibodies. But the duration of such latent infections has been uncertain. Now a study has shown that some people may carry the AIDS virus for three years or longer without its being detected by widely used antibody screening tests. If the results are confirmed, they could mean that latent AIDS infection is more common than was once believed.

The study, reported last week in the New England Journal of Medicine, followed 133 men without AIDS antibodies who continued to engage in high-risk sexual activity. A team led by researchers at the University of California, Los Angeles, found that of 31 who carried the AIDS virus, 27 had not produced antibodies up to three years after the virus was detected. While the study raises questions about the effectiveness of current screening tests, which zero in on AIDS antibodies and not the virus itself, there is a bright side: some infected people may remain healthy for longer than was previously thought.