Meningitis causes inflammation of the lining surrounding the brain and spinal cord. High fever, headache, and stiff neck are common symptoms of meningitis in anyone over the age of 2 years. Other symptoms include nausea, vomiting, discomfort looking into bright lights, sleepiness, confusion, or seizures. In infants, the classic symptoms of headache and stiff neck are difficult to detect and the infant may only appear lethargic, sleepy, and irritable, or may have a tense, bulging fontanelle, or may be feeding abnormally.
Meningitis is usually caused by a virus or bacteria. Viral meningitis is generally less severe and does not require specific treatment. Bacterial meningitis is a severe illness that may result in brain damage, hearing loss, or death if not treated promptly.
People who have been in close contact with someone who has meningitis are at increased risk, as some types of bacteria such as meningococcus are spread by oral secretions. People with weakened immune systems as a result of under-nutrition or infections such as AIDS are at greater risk for acquiring meningitis. Infants are also at greater risk for meningitis because their immune response against some types of bacteria is immature.