Neisseria meningitidis only infects humans; there is no animal reservoir. The bacteria can be carried in the throat and sometimes, for reasons not fully understood, can overwhelm the body's defenses allowing infection to spread through the bloodstream to the brain. It is believed that 10% to 20% of the population carries Neisseria meningitidis in their throat at any given time.
N. meningitidis inhabits the mucosal membrane of the nose and throat, where it usually causes no harm. Up to 5-10% of a population may be asymptomatic carriers.Each year, approximately 1,000 people in the Canada get meningococcal disease, which includes meningitis and septicemia (blood infection).
Initial diagnosis of meningococcal meningitis can be made by clinical examination followed by a lumbar puncture showing a purulent spinal fluid. The bacteria can sometimes be seen in microscopic examinations of the spinal fluid. The diagnosis is supported or confirmed by growing the bacteria from specimens of spinal fluid or blood, by agglutination tests or by polymerase chain reaction (PCR).
Major research on disease:
Active Surveillance for Adverse Events After a Mass Vaccination Campaign With a Group A Meningococcal Conjugate Vaccine (PsA-TT).The identification of the serogroups and susceptibility testing to antibiotics are important to define control measures.As with all vaccines, there can be minor reactions, including pain and redness at the injection site, headache, fatigue or a vague feeling of discomfort.