(2) The same bacteria strain is one of two main causes of bacterial meningitis; the other is Streptococcus pneumoniae. When the causative bacteria strain is N. meningitidis the condition is known as meningococcal meningitis. Usually meningococcal meningitis and meningococcal infection of the blood coexist in the same patient, but in recent years there has been an in the number of patients whose infection is confined to blood and have, like Kevin, no infection of the meninges. (3) Yes. Neisseria meningitidis is present in the nose and throat of around 10-20% of the healthy population.