From the Centers for Disease Control and Prevention. Risk for meningococcal disease associated with the Hajj 2001.
D000846:Anniversaries and Special Events; D004196:Disease Outbreaks; D006801:Humans; D007514:Islam; D008589:Meningococcal Infections / Q000453:epidemiology*; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D014195:Travel; D014481:United States