Haemophilus influenzae meningitis is a bacterial infection of the membranes covering the brain and spinal cord (meninges).
H. influenzae meningitis is caused by Haemophilus influenzae bacteria. This bacteria should not be confused with the disease influenza, an upper respiratory infection caused by the influenza virus.
Before the Hib vaccine became available, H. influenzae was the leading cause of bacterial meningitis in children under 5 years of age. Since the introduction of the vaccine in the U.S., H. influenzae now occurs in less than 2 in 100,000 children. It still causes 5% - 10% of bacterial meningitis cases in adults.
H. influenzae meningitis may come after an upper respiratory infection. The infection usually spreads from the respiratory tract to the bloodstream, and then to the meninges. At the meninges, the bacteria produce infection and inflammation, causing serious illness and sometimes death.
Risk factors include:
For any patient with meningitis, it is important to perform a lumbar puncture ("spinal tap"), in which spinal fluid (known as cerebrospinal fluid, or CSF) is collected for testing.
Other tests include:
Treatment must be started as soon as meningitis is suspected. H. influenzae meningitis should be treated with antibiotics given through a vein (IV).
Steroid medication may also be used, mostly in children. Steroids are given to reduce hearing loss, which is a common complication of meningitis in children.
The likely outcome is good with early treatment. However, 3 - 5% of patients do not survive.
Contact your health care provider or go to an emergency room if you experience symptoms of H. influenzae or if you notice these symptoms in your child. Meningitis can quickly become life-threatening.
To protect infants and young children:
To prevent infection after being exposed to H. influenzae meningitis:
H. influenzae meningitis; H. flu meningitis