While the<unk>  influenzae bacteria are unable to survive in any environment outside of the human body, humans can carry the bacteria within their bodies without developing any symptoms of the disease. It spreads through the air when an individual carrying the bacteria coughs or sneezes. The risk of developing<unk>  is most directly related to an individual's vaccination history, as well as the vaccination history of the general public. Herd immunity, or the protection that unvaccinated individuals experience when the majority of others in their proximity are vaccinated, does help in the reduction of meningitis cases, but it does not guarantee protection from the disease. Contact with other individuals with the disease also vastly increases the risk of infection. A child in the presence of family members sick with<unk>  or carrying the bacteria is 585 times more likely to catch<unk> . Additionally, siblings of individuals with the<unk>  influenzae meningitis receive reduced benefits from certain types of immunization. Similarly, children under two years of age have a greater risk of contracting the disease when attending day care, especially in their first month of attendance, due to the maintained contact with other children who might be asymptomatic carriers of the Hib bacteria.
Haemophilus meningitis
Herpesviral meningitis
Lemierre's syndrome
Eastern equine encephalitis
Fungal meningitis
Mollaret's meningitis
Tick-borne encephalitis
Diphtheria