By Andrea Shalal-Esa

WASHINGTON (Reuters) - US-based Advanced Bionics Corp. on Thursday warned that the inner-ear implants it makes to help deaf people hear may also put them at greater risk for potentially fatal meningitis and urged its customers to get vaccinated.

"We're making very strong recommendations to all of the individuals who use our cochlear system to be vaccinated against various pneumococcal diseases," said Douglas Lynch, spokesman for the Valencia, California-based company, one of three manufacturers of the devices.

The Food and Drug Administration issued a public health notification on Wednesday noting that 25 adults and children with cochlear implants had been diagnosed with meningitis worldwide and it was aware of nine deaths in these cases.

Surveys of cochlear implant centers currently under way suggested that there were additional, unreported cases of meningitis among cochlear implant patients, the FDA said.

The FDA recommended that physicians consider giving patients antibiotics before implantation and urged them to diagnose and treat ear infections promptly in implant patients.

"Cochlear implant candidates, as well as those already implanted, may benefit from vaccinations against organisms that commonly cause bacterial meningitis, particularly streptococcus pneumoniae and haemophilus influenzae," the FDA said, urging prompt reporting of any cases of meningitis.

The FDA said the onset of meningitis symptoms ranged from less than 24 hours to greater than 5 years from the time of implantation. It said some 60,000 people worldwide had received the implants, which contain electrodes that are positioned in the inner ear, or cochlea, to activate auditory nerve fibers to allow transmission of sound signals to the brain.

Advanced Bionics has sold some 10,000 cochlear implants since the FDA first approved the device in 1996.

Australian manufacturer Cochlear Ltd., the leading manufacturer of the devices, has sold over 40,000 devices in the past 20 years.

Jim Miller, president of Cochlear Americas, the US division, said he was not aware of any meningitis-related deaths linked to the company's products in that entire period.

ANTIBIOTIC TREATMENT ENCOURAGED

Miller noted meningitis was a complication of any inner-ear surgery, and some deaf patients were at even greater risk due to malformations of the inner ear. But he said his company's research showed the incidence of meningitis in implant patients was not greater than that of the general public.

Still, Miller lauded the FDA's effort to raise awareness about the risks of meningitis, and said his company routinely recommended prophylactic antibiotic treatment in the period immediately before and after implantation surgery.

No comment was immediately available from the third manufacturer of cochlear implants, Austrian-based MED-EL.

Advanced Bionics first raised the issue of a possible increased risk for meningitis with the FDA on June 28, Lynch said, noting that the company had launched an independent investigation after observing "a few cases of meningitis."

Lynch said there was still no evidence of "a definitive link," but the company was reviewing its device and components to determine if they could be linked to an increased risk.

He noted that the company already warned patients about the risks of contracting meningitis as a result of the surgery.

"We want to educate everyone who gets implanted. It's prudent to get vaccinated," said Lynch. "It makes good sense."

Meningitis is an infection of the membranes surrounding the brain that can be treated when diagnosed early. It can be deadly in some cases, especially if diagnosed late. The disease can be difficult to diagnose in young children, whose symptoms include fever, irritability, lethargy and loss of appetite.

Older children and adults may also have headaches, stiff necks, nausea and vomiting. Younger patients and the elderly were the most vulnerable to meningitis, the FDA said.