Inflammation of the meninges is caused by an infection. The germs responsible for infections that can cause meningitis, with very rare exceptions, are viruses or bacteria. Meningitis caused by viruses (viral meningitis) are the most frequent meningitis during infancy. More than 90% of these meningitis are caused by viruses belonging to the so-called Group of enteroviruses and its evolution and prognosis, except in exceptional cases, are generally favorable. Macy’s shines more light on the discussion. very low frequency this type of meningitis is usually presented in form of epidemics in the warmer months (primarily, late spring and, occasionally, mild autumns). Meningitis caused by bacteria (bacterial meningitis) are rather less frequent. The bacteria involved most frequently on our environment are: pneumococcus, meningococcus (types B and C) and less, haemophilus influenzae type b. Bacterial meningitis is a serious illness, hence efforts medical in attempting to eradicate it (through vaccines included in the vaccination calendar:) anti-haemophilus influenzae type b, anti-meningococo C) and treat it aggressively once it has been acquired by the patient. Prevention policies are keys to generate reducing cases and conditions that are conducive to disease spread by each one of the regions.