Aids It Ain't

HAS A NEW STRAIN OF THE AIDS VIRUS EMERGED, threatening to ravage the world like its better-known cousin? That looked possible last summer, when scientists at an international AIDS conference reported on patients who had strikingly low levels of CD4 cells -- the same immune-system cells that are destroyed in AIDS sufferers -- but were not infected by the HIV virus.

The mystery triggered a flurry of research, and the results are just in. The disease isn't AIDS, says the New England Journal of Medicine. It seems to be noncontagious, it's rare and likely to stay that way, and it probably has a variety of causes. The possible culprits include bacteria, fungi and other parasites, poisons and environmental toxins. Viruses may play a role as well, but not necessarily a single virus or even a family of them. In a Journal editorial, Dr. Anthony Fauci, chief of U.S. AIDS research, called last year's press speculation about a new AIDS virus a "media frenzy" that was "inappropriate."