In 2006, an epidemic of chikungunya caused more than one hundred deaths on Reunion Island. This health crisis constituted a test on several levels. The mosquito, defined before the health crisis as a local ally by the Creoles, as it was used to mark boundaries between them, the Zoreils and tourists, took on the status of foreign enemy during the epidemic. The mosquito thus led tourists and locals to join against a common threat. The epidemic constituted a test that allowed for the development of a shared framework of commendable behavior: the principle of engagement to relieve the sick and the principle of restraint made it possible to obtain recognition regardless of ethnic origin. Six years after the crisis, the representations before the epidemic are partly restored at the political level but have been permanently modified on the level of interindividual exchanges.