Mystery illness

Scientists are reporting cases of a mysterious illness that acts like AIDS, even though patients are not HIV positive.

Most cases have been in Asia, but a few have been reported in the U.S.

At this point, scientists do not believe it runs in families or is contagious.

Doctors say it appears to be a form of adult-onset acquired immune deficiency.

Patients often suffer from infections, and some have died.

The illness is sometimes mistaken as tuberculosis.