Meningococci are diverse organisms and are usually commensal bacteria present in nasopharynx in humans. Only a minority of the isolates cause invasive disease. Meningococci associated with invasive disease elaborate a capsule, which provides protection from desiccation during transmission and aids in the evasion of host immune mechanisms.
The human naso-oropharyngeal mucosa is the only natural reservoir of N. meningitidis . Meningococci are transferred from one person to another by direct contact or via droplets. During periods of endemic infection, 8 to 20 % of adults are asymptomatic nasopharyngeal carriers of strains of N. meningitidis, most of which are not pathogenic.
In early 2005, spurt of cases of meningoccemia and meningitis due to N. meningitidis serogroup A have been reported from Delhi and adjoining areas. As of June 17, 2005, 429 probable cases of meningococcal disease have been reported. Among these, 128 cases have revealed microbiological evidence of meningococci. Of these, 40 cases were culture positive for meningococci.
As this infection spreads to others very easily, all those who have been in contact with some diagnosed with meningococcal infection should contact their physician. In many cases, an individual who has been in contact with someone with meningococcal infection may be given an antibiotic to help prevent meningococcal disease.
Major research on disease:
Infectious Cognition: Risk Perception Affects Socially Shared Retrieval-Induced Forgetting of Medical Information.Meningococcal meningitis can be fatal or cause great harm without prompt treatment; as many as one out of five people who contract the infection have serious complications.