Menigitis is an inflammation of the meninges which are the membranes that cover the brain and spinal cord. Most of the time, the inflammation is caused by bacteria or viruses while the less common causes include fungi, protozoa, and other parasites. Sometimes certain medications, cancers, or other diseases can inflame the meninges, although such noninfectious cases of meningitis are very rare.
Bacterial menigitis occurs in people of all ages but is more common in infants and young children and people above age 60. Teenagers and young adults are slightly more at risk for the disease because of time spent in close contact with many of their peers. Viral meningitis occurs in people of all ages, although it is more common in children. Many of the bacteria or viruses that can cause meningitis are fairly common and are more often associated with other everyday illnesses. But it is possible that they spread to the meninges from an infection in another part of the body. From there the microorganisms can enter the bloodstream, travel through the body, and enter the central nervous system.
Bacterial menigitis is less common than viral menitgitis but is usually much more serious and can be life-threatening if not treated right away. There are many different types of bacteria which can cause menigitis such as Group B Streptococcus, Escherichia coli and LIsteria monocytogenes. which are common in new borns. Streptococcus peumoniae and Neisseria meniingittdis are more frequent in children 2 months or older. The complications of bacterial menigitis can be severe and include neurological problems such as hearing loss, visual impairment, seizures, and learning disabilities. Other parts of the body affected may be the heart, kidneys, and adrenal glands. Although some children develop long-lasting neurological problems from bacterial menigitis, most who receive prompt diagnosis and treatment recover fully.
Viral menigitis is more common and far less serious comparied to bacterial menigitis. It often remains undiagnosed because its symptoms are similar to those of the common flu. Most cases of viral menigitis are associated with viruses that typically cause the stomachflu. However, many other types of viruses can also cause menigitis. The majority of cases of viral menigitis resolve with no complications.