The most impoant source of Infection for meningococci is

The human nasopharynx is the only reservoir of the Meningococcus. Natural infection is limited to the nasopharynx. Asymptomatic nasopharyngeal carriers rarely contract the illness but serve right infect their contacts. During the inter-epidemic period, the carrier rate is 5-10 percent. An increase in carriers rate heralds the onset of an epidemic. During epidemics, the carrier rates of closed communities may go up to 90 percent. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 232