An ‘Impossible’ Disease Outbreak in the Alps

In March 2009, after a long night on duty at the hospital, Emmeline Lagrange took a deep breath and prepared to place a devastating phone call. Lagrange, a neurologist, had diagnosed a 42-year-old woman with amyotrophic lateral sclerosis, or ALS. The woman lived in a small village in the French Alps, an hour and a half drive away from Lagrange’s office in Grenoble Alpes University Hospital. Because ALS is rare, Lagrange expected that the patient’s general practitioner, Valerie Foucault, had never seen a case before. Snow fell outside Lagrange’s window...