Disease with a funny name

AS is not a new disease. The spines of 4,000-year-old mummies excavated from Egyptian tombs show conclusive evidence of the affliction. Yet today, because of the lack of proper diagnosis, no one knows exactly how many people are affected. At present, 500,000 people are reported to have AS in this country and studies strongly indicate it may be much more.
AS is extremely difficult to diagnose in its early stages. Studies show the average spondylitis victim endures many years of misdiagnosis before their condition is correctly identified, even though it is the third most common form of chronic arthritis in the United States. AS is not restricted to humans either. Primate studies indicate gorillas also suffer from a form of AS.

Reference:
Winston, C. "The mysterious back disease." AFAA's American Fitness 7.n2 (March-April 1989): 6