Bacterial (septic) meningitis is caught from people who are carriers of the bacteria, but the victims are usually weak, ill, under stress or have their ability to resist infection reduced in some way.
The most common forms of bacterial meningitis is caused by Haemophilus influenzae B (HiB), while the most serious is meningococcal meningitis (caused by Neisseria meningitidis). It is a much more serious condition, with the severity and symptoms varying depending upon which type of bacteria is responsible.
Complications include permanent deafness in one or both ears, damage to different parts of the brain, heart or kidney damage, arthritis and the excess production of cerebrospinal fluid which can put pressure on the brain (hydrocephalus). The worst complication is intravascular coagulation, which involves the blood clotting within the arteries and blocking them.