[Chikungunya and urban sprawl on Reunion Island].

The proportion of unsanitary housing in French overseas departments is much higher than in mainland France. Reunion Island is no exception to this fact. Between 80 and 90% of housing in Reunion Island was built by squatters with no legal claim or deed to the property. This has resulted in uncontrolled urban sprawl with living conditions reminiscent of those in developing countries. The absence of adequate drainage systems for sewage and rain water and the lack of properly organized garbage disposal that characterizes these sprawl areas constitutes a particularly favorable breeding ground for vector-borne diseases, especially chikungunya. Thus, implementing measures to control this type of settlement and to relocate of people out of existing sprawl areas constitutes a significant tool to control this epidemiological risk. Up to now, public officials have shown a clear reluctance to intervene in sprawl areas despite good knowledge of their location. On June 26th of this year, a law containing provisions relative to the control of urban sprawl and unsanitary housing in overseas departments and territories will come into effect. This law should provide public officials with the legal basis that has up until now been lacking to take action. Persistence in the "wait-and-see" attitude could lead to condemnation by French or European courts.