Study Confirms Meningitis-Cochlear Implant Link
But researchers say risk is small and manageable
(HealthDay is the new name for HealthScoutNews.)
WEDNESDAY, July 30, 2003 (HealthDayNews) -- A new study by government scientists confirms reports linking cochlear implants to an increased risk of meningitis, but researchers regard that risk as small and manageable.
"The rate of meningitis for children who received cochlear implants is higher than it is among the general population," says study author Jennita Reefhuis, a researcher with the National Center on Birth Defects, a division of the U.S. Centers for Disease Control and Prevention. "However, it is unknown how much of the risk is due to the cochlear implant and how much is due to other factors."
For example, Reefhuis notes meningitis is more common among deaf children than it is in the general population.
A cochlear implant is an electronic device that is surgically placed in the cochlea (inner ear). The device contains electrodes that activate nerve fibers so sound signals can be transmitted to the brain. These implants can help children and adults with hearing loss perceive sounds and learn to speak. In the United States, almost 10,000 children and 13,000 adults with severe to profound hearing loss have cochlear implants.
The study looked at 4,264 children under 6 years of age who received a cochlear implant between Jan. 1, 1997, and Aug. 6, 2002.
The researchers identified 29 cases of bacterial meningitis in 26 children (three children had two bouts of the disease). Of these children, 15 had meningitis caused by the Streptococcus pneumoniae bacterium. In the general population, less than one case would be seen in a group this size, according to the report.
Of the 29 cases, nine occurred within a month following the implant, while the other 20 cases occurred up to 36 months after surgery. The study, which was also conducted by researchers from the U.S. Food and Drug Administration and the states of Texas and New York, appears in the July 31 issue of the New England Journal of Medicine.
In children who have a cochlear implant, the risk of meningitis is 4.5 times higher when a device called a "positioner" is used, Reefhuis says. She notes that due to this increased risk, the positioner has not been used for the past year and is no longer being produced.
Reefhuis says physicians should be sure patients who are candidates for a cochlear implant are up-to-date on their vaccinations. There are special recommendations for meningitis vaccination for cochlear implant patients, she adds.
Physicians should also assess their patients for risk factors for meningitis. And after surgery, they should be on the watch for any signs of meningitis, Reefhuis says.
Parents considering a cochlear implant for their child or adults considering one for themselves should discuses the advantages and risks of having the implant with their health-care provider, she advises.
"These are really wonderful devices that can really help patients perceive sound and help develop speech," Reefhuis adds.
George A. Gates, a professor of otolaryngology/head and neck surgery at the University of Washington in Seattle, comments that because the risk of meningitis is so small it should not be a factor in deciding whether to have a cochlear implant.
"The risk for meningitis is not much greater than for people who don't have a cochlear implant," he says.
Gates and his colleague, Dr. Richard T. Miyamoto from the Indiana University School of Medicine, express their view in an accompanying editorial in the journal.
Cochlear implants are extraordinarily valuable, and the quality of life gained make the procedure very cost-effective, Gates says. "The procedure restores people back to employability and to normal communication and out of the world of deafness," he says.
"Cochlear implants have been the greatest thing since sliced bread for people with severe to profound hearing loss and for whom hearing aids don't improve their understanding," Gates adds. "It is hard to imagine how isolated you can be with hearing loss. It has a very powerful effect on the quality of life."
To learn more about cochlear implants, visit the National Institute on Deafness and Other Communication Disorders. To learn more about the connection between the implants and meningitis, visit the U.S. Food and Drug Administration.