The oft derided theory that HIV is not a trigger for full blown AIDS is enjoying a resurgence. About 30 recent cases from around the world reveal a new AIDS like illness which has no trace of HIV.

A hastily convened meeting by the Centers for Disease Control at Atlanta, Georgia, agreed to name the new phenomenon "CD4 T-lymphocyte depletion in persons without evident HIV infection", or just mystery virus, for short.

The meeting told a puzzled media that the new condition was not infectious and presented no danger to public health.

Since 1989, 21 cases of CD4 have been reported in the medical literature. At a recent conference in Amsterdam, nine further cases were unveiled, thus bringing the total known cases to 30.

Of these cases, 21 there were 21 men and nine women from 18 to 70 years of age. Five of the victims were homosexual or haemophiliac; of the remaining 25, 12 had non AIDS defining illnesses, and 13 had. Twenty five of the victims were white, and 54 per cent had no apparent risk factors for contracting HIV.

At the Atlanta meeting, one scientist claimed to have found an infectious particle from the virus, which resembles one present in patients with Sjogren's syndrome, many of whose symptoms resemble those of AIDS.

Absent was any discussion of the possibility that this new mystery AIDS or, indeed, AIDS itself isn't caused by a virus at all.

Despite assurances from the panel at Atlanta over the safety of blood supplies, the watchword over this new syndrome for American blood banks is "alertness without alarm".