What is viral meningitis? Meningitis is an inflammation of the meninges (the cadaverous lining of tissue covering the brain and spinal cord) caused by an infection of the cerebrospinal fluid. Viral meningitis is relatively common, and is usually mild, and though it can occasionally be life-threatening, it should not be confused with the more strict bacterial meningitis. It is occasionally referred to as 'aseptic' meningitis, and can sometimes go undiscovered because its symptoms can mimic that of the 'flu. Some special viruses are celebrated to cause viral meningitis: specifically mosquito-borne viruses, common intestinal viruses (enteroviruses), and sometimes the herpes simplex virus. The method of transmission depends upon the virus responsible, but person-to-person contact and insect transmission are the usual forms. It tends to be more usual in children low the age of five, though it does occur in adults.