Meningitis:- Definition:- Meningitis is an inflammation of the area surrounding your brain and spinal cord meninges. It’s sometimes called spinal meningitis. Your meninges protect your brain and spinal cord from injury and provide support and structure. They contain nerves, blood vessels and protective fluid (cerebrospinal fluid). Infectious disease like viruses and bacteria, and non-infectious conditions, like cancer or head injuries, can cause meningitis. Pathogenesis:- Infectious causes are bacteria, viruses, fungi, parasites and the ameba Naegleria fowleri. Non-infectious causes include diseases, certain medications and other conditions. Causes of bacterial meningitis Streptococcus pneumonia. Group B Streptococcus . Neisseria meningitides. Haemophilus influenza. Listeria monocytogens. E.coli. Mycobacterium tuberculosis Causes of viral meningitis Non-polio enteroviruses. Mumps. Herpesviruses (including those that cause mononucleosis,chikenpox shingl...