A massive, decade-long medical study has removed some lingering doubts that the neurological disease multiple sclerosis (MS) is linked to a common viral infection. For years, research findings have pointed toward the connection, but whether the infection is a cause, a result, or unrelated to MS has remained an open question.
Now, in a large-scale investigation into that question, researchers have found a statistical smoking gun linking risk of the disease to the body's long-lasting immune response to Epstein-Barr virus.
Epstein-Barr, a herpes virus, infects more than 9 in 10 people worldwide. Fortunately, most tots who catch it develop just a mild flu, and people infected later in life usually come down with nothing worse than mononucleosis (SN: 10/10/98, p. 229).