A puzzling disease that is affecting only Asians is being described by researchers as similar to AIDS, but not contagious. Dr. Sarah Browne, with the National Institute of Allergy and Infectious Diseases, calls the new disease “absolutely fascinating” but says it’s an acquired immune deficiency that isn’t spread through a virus, like HIV/AIDS. According to Browne’s report published Thursday in The New England Journal of Medicine, the illness usually develops around age 50, but doesn’t appear to be passed down genetically. The first cases began to appear in 2004, and doctors have developed a method to tame infections, but an unknown number have already died from the disease. Researchers have concluded that genetic and environmental factors must be contributing to the illness, since all the patients so far have been Asian or born in Asia.