WHO Guideline. Since 2010, countries in the meningitis belt have started to introduce a new serogroup A meningococcal conjugate vaccine conferring individual protection and herd immunity. Following the successful roll-out of this vaccine, epidemics due to Neisseria meningitidis serogroup A (NmA) are disappearing, but other serogroups (e.g. NmW, NmX and NmC) still cause epidemics, albeit at a lower frequency and of a smaller size. Due to these changes, WHO organized the review of the evidence to provide recommendations for epidemic control, related to operational thresholds for investigation and response to outbreaks, the use of rapid diagnostic tests, antibiotic regimens in epidemics, and prophylaxis for household contacts of cases