Low meningitis rates with cochlear implants, but vaccinations and prompt treatment critical.

Children with severe to profound hearing loss who have received cochlear implants are at increased risk of bacterial meningitis, but the complication is quite rare, according to a report in the July 31 issue of the New England Journal of Medicine.

Nonetheless, "parents and health care providers should ensure that all children who receive cochlear implants are appropriately vaccinated and are then monitored and treated promptly for any bacterial infections after receiving the implant," wrote Jennita Reefhuis, PhD and colleagues at the Centers for Disease Control and Prevention (CDC) in Atlanta.

Since June of 2002, the 3 manufacturers of these implantable hearing devices have notified the Food and Drug Administration (FDA) of reports of bacterial meningitis after implantation. The FDA, CDC, and state and local health departments subsequently conducted studies to determine the rate of this complication and to examine risk factors.

The researchers identified 29 episodes of bacterial meningitis among 4,264 children who received a cochlear implant in the United States between 1997 and August of 2002. Since September, 6 additional cases were reported. Nine episodes occurred around the time of surgery, while the rest developed more than 30 days after surgery. Children who had an implant with a Silastic positioner and those with inner-ear malformation and a cerebrospinal fluid leak were at higher risk for the infection. The company that marketed the implants with a positioner recalled those products in July of 2002.

Reefhuis and coauthors recommended that patients be vaccinated at least 2 weeks prior to surgery against Streptococcus pneumoniae and Haemophilis influenzae, and they stressed that parents and doctors must be alert to meningitis symptoms. The researchers did not advocate removal of the implant, although this was done in 3 of the children.

George Gates, MD of the University of Washington in Seattle and Richard Miyamoto, MD of the Indiana University School of Medicine in Indianapolis supported these recommendations in an accompanying editorial. They also noted that "for most adults and children with severe-to-profound hearing loss, the use of an implant is the only viable choice for effective oral communication," and that complications are rare.