Meningitis

Some time ago, I had an argument with Kriza, about meningitis, its spread and so. I was vaccinated against the disease, just before my departure to Argentina and the physician was telling me a bit about it, but Kriza disputed it.
So: In general, meningitis is inflammation of meninges (the protective layers on the brain) - that means it can be caused by various causes - most often viruses and bacteria (but for example abuse of some drugs may cause it as well). The viral meningitis tends to be less severe (like common flu), while bacterial infections are a little bit less common, but much more dangerous.
Actually, when talking about meningitis, most often it means the meningococcal one (caused by neisseria meningitidis). It's also the one I was vaccinated against. Actually, there are several subtypes of the bacteria and the vaccination include just some of them.
It spreads mostly by respiratory droplets (coughing, spitting), it's often called the disease of the young, as it's most widespread among teenagers, while it can affect any age group. In average, the bacteria is present at some 10% of population, the disease starts when one's immune system is weakened (in other words, it's not clear, what exactly causes the outbreak).
Up to 10% of patients die, another 10% retain permanent damage.
Symptoms include rash, fever, headache and light avoidance.