Since the beginning of 2006, a crippling mosquito-borne disease has shown an explosive emergence in nations in the Indian Ocean area. By March 7, 2006, 157,000 people had been infected in the French island La Réunion, and the disease had spread to the islands of Seychelles, Mauritius, and Mayotte (French). Subsequently, the disease appeared in India, China, and European countries. The World Health Organization is taking measures to assist in fighting the epidemic. This article describes the disease, its recent emergence, and the current epidemic.