Two health areas were excluded for inaccurate data collection, and 2 other were randomly disqualified as investigators previously decided to conduct the survey in ≤ 4 areas. The mode of randomization aimed at includes no more than 1 health area per district. Finally, investigators retained 4 health areas representing 4 out of 6 districts of Douala. Thus, the sampling of 240,384 inhabitants will be monitored prospectively. All administrative staff and community-healthcare committee, the so-called " comité de santé" (COSA) of each health area will be a key component of the research team, helping identify every case of death in the area of concern. Every case of death will be reported by the staff of COSA in a specific questionnaire form. In addition to the deaths noted by members of each COSA, investigators will pay attention with all notices of deaths in local newspapers, radio, interrogation of health area residents, and death certificates from local medical centers.