It is admitted that real time surveillance system permits to reduce delay of outbreak detection and preventive measures implementation (1) . It is usually based on prediagnostic numeric data collection and transmission (2) . ASTER (Alerte et surveillance en temps réel) is a real time surveillance system for French Armed Forces deployed in French Guiana and Djibouti ( Fig. 1) , constituted by 2 kinds of networks: several declaration networks and one analysis network (3). On June 2011, an outbreak occurred among a French Army Regiment in Djibouti, which has permitted to evaluate ASTER in real conditions.