Mysterious illness mimics AIDS symptoms

The patients' immune systems become damaged, leaving them unable to fend off infections as healthy people do.

What triggers this isn't known, but the disease does not seem to be contagious.

“This is another kind of acquired immune deficiency that is not inherited and occurs in adults, but doesn't spread the way AIDS does through a virus,” said Dr Sarah Browne, a scientist at the National Institute of Allergy and Infectious Diseases.

She helped lead the study with researchers in Thailand and Taiwan, where most of the cases have been found since 2004.