Clostridium difficile is the leading cause of nosocomial infectious diarrhea in adults. In 2006, an outbreak of C. difficile infections linked to a particularly virulent strain, known as 027, affected several healthcare facilities in northern France. Strain 027 had previously been responsible for similar outbreaks in North America, particularly in Quebec. With the support of the Consulate General of France in Quebec City and the Quebec Ministry of International Affairs, the French Institute for Public Health Surveillance and the Quebec National Institute of Public Health sought to pool their expertise in the detection, surveillance, and control of C. difficile infections. The seminar, held on November 28, 2007, at the Cité des sciences et de l'industrie (Paris), brought together several partners from both institutes and provided an opportunity to take stock of the current state of scientific knowledge regarding these infections and their prevention methods. It was primarily aimed at healthcare professionals, particularly those in hospitals, who are confronted with this emerging infectious disease. (R.A.)