August 8, 2002
Every year, about 2,000 kids, teens, and adults in the United States with hearing loss receive cochlear implants, special devices that are surgically implanted into the ear. The cochlear implants bypass the person's damaged inner ear and send signals directly to the auditory nerve. A small microphone behind the ear picks up sound waves and sends them to a receiver that has been placed under the scalp, and this receiver then transmits impulses to the auditory nerve through electrodes placed in the cochlea. A cochlear implant does not transmit speech clearly, but it does allow a person to be aware of sounds that may be interpreted as speech.
Although cochlear implants can allow kids and teens with hearing impairment to hear some sounds, it now appears that they may also carry an increased risk of getting bacterial meningitis. Bacterial meningitis occurs when bacteria infect the lining of the surface of the brain, causing symptoms such as fever, irritability, headaches, stiff neck, nausea, and vomiting.
On July 24, the U.S. Food and Drug Administration (FDA) reported that at least 25 people with cochlear implants, ranging from 21 months to 63 years old, have been diagnosed with bacterial meningitis. More people may be affected, but some cases of meningitis that have occurred in people with cochlear implants may not have been reported. Of the 25 reported cases, nine people with cochlear implants have died as a result of the infection.
What's causing this serious infection? Out of 11 people with meningitis for whom culture results were available, Streptococcus pneumoniae, also known as Pneumococcus, was positively identified in seven people. In the other four, the bacteria identified were likely Pneumococcus as well. Only five people had records of their immunizations and none had received the pneumococcal vaccine.
FDA researchers believe that people with cochlear implants may be at greater risk for meningitis for several reasons. Some people who are hearing impaired have inner ear abnormalities that would make them more at risk for infection, even without the implant. In addition, poor health, surgical complications, and a history of ear infections prior to implantation may also put children and teens with cochlear implants at higher risk for developing meningitis. Finally, the cochlear implant itself may be a place where bacteria adhere and may be a source for the infection.
If your child is a candidate for cochlear implant surgery, your child's doctor may recommend antibiotics before surgery to reduce the risk of an existing infection spreading during surgery. In addition, your child's doctor should treat ear infections, or otitis media, as soon as symptoms appear. This may prevent the spread of any bacterial infections in children with cochlear implants.
Be sure your child's vaccinations are up to date, including immunizations for Haemophilus influenzae (HIB) and Streptococcus pneumoniae. The current recommendations for the pneumococcal vaccine can vary depending on your child's age and the vaccine used. Because your child may be at higher risk for serious infection, seek medical care if your child is sick and be sure to remind all caregivers that your child has a cochlear implant.
Reviewed by: Mary L. Gavin, MD
Date reviewed: August 2002
