All children who receive cochlear implants to restore their hearing should be vaccinated against meningitis, doctors have warned.
Thousands of children have received cochlear implants
It follows a study in the United States which found that children who receive the implants may be at increased risk of developing the potentially fatal disease.
The implant consists of an electrode which is permanently inserted into the inner ear to enable patients to hear.
Over 3,300 Britons, many of them children, have benefited from the device.
Previous studies have suggested that some implants may increase the risks of patients developing meningitis.
The UK's Medical Devices Agency issued guidelines last August recommending meningitis vaccines for everyone who receives an implant.
Those guidelines appear to be backed up by this latest study.
Dr Jennita Reefhuis and colleagues at the US National Center on Birth Defects studied 4,264 children who had received cochlear implants between 1997 and 2002.
All of the children were less than six years of age when they received the implant.
They identified 26 children who had gone on to develop bacterial meningitis. This was 30 times higher than the general population.
The researchers found that certain types of implants, namely those with "positioners", carried an increased risk of meningitis.
These positioners push the electrode against the wall of the cochlea, the
spiral-shaped organ that normally translates sounds into electrical impulses the brain can understand.
Advanced Bionics Corporation, which manufactures the implants, withdrew two brands containing a "positioner" last year.
It followed a report from the US Food and Drug Administration which linked these implants with bacterial
It found that 91 patients who had received the implants had developed meningitis. Of these, 17 had died.
However, this latest study suggests that other types of implants may also carry an increased risk of developing meningitis.
They found that meningitis rates were 16 times higher than expected in patients who received a cochlear implant which did not have a "positioner".
They suggested that this could have been because of a malformed cochlea or because of a leak involving the fluid
that bathes the brain.
Writing in the New England Journal of Medicine, they said their findings highlighted the need for children who receive implants to be vaccinated.
"Parents and healthcare 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."
Cochlear implants use a microphone to pick up sounds which are then transferred to an implanted receiver.
These, in turn, deliver electrical impulses into the cochlea so they can be
relayed to the brain.