Five regions are affected: Franche-Comté, Lorraine, Côte-d'Or and Haute-Marne, Picardy, and the Ardennes. Since 1990, the Ardennes has been the hardest-hit area, accounting for 40% of cases in 1990 and 57% of cases during the 1993 outbreak. Overall, nearly 40% of French cases originate from this area... From January 1994 to March 1996, 30 patients were therefore hospitalized in the internal medicine or nephrology departments of the Charleville-Mézières hospital, and 1 patient was treated by their primary care physician.