This study showed that the carriage rate is nul or low in collectivity not in close contact, but high in collectivity in close contact (schools, particularly coranic schools). In this later case, the duration of the carriage may reach several weeks (2 to 6 in our study) at variable rates (3.7 to 9.6%; 12.5 to 62.5%; 14.3 to 42.9% according to the coranic school visited). For the strains of N. meningitidis serogroup C isolated, the rate of resistance to sulfamides and cotrimoxazole is 86.8%. These results explain why during epidemics, it is necessary to close schools and avoid to use for the chemoprophylaxis, sulfamids and their associations because of resistance.