In a study between January 1, 1997 and August 6, 2002 involving 4264 children who had received cochlear implants before the age of 6, the incidence of meningitis caused by Streptococcus pneumoniae was 138.2 cases per 100,000 person-years which was more than 30 times the incidence of similar aged children in the general U.S. population. Before 2002, the occurrence of bacterial meningitis after cochlear implantation was thought to be uncommon, but in 2002, a spike of cases appeared in North America and Europe. Post-implantation bacterial meningitis was strongly associated with the use of an implant with a 2-piece cochlear implant, with one piece being the electrode carrier and the 2nd being a device to hold the electrodes close to the center of the cochlea.1 This type of cochlear implant device went off the market about that time. While many of these cases involved use of this particular implant that had an extra piece of silicone to position the electrodes closer to the hearing nerves, cases were found involving devices from all 3 of the most commonly used manufacturers. These data led to studies of the cause of the meningitis and means of treatment and prevention.2 By 2008, 118 of the 60,000 people worldwide who had received a cochlear implant over the prior 20 years had acquired meningitis, causing concern in the international medical community.3 Vaccines in cochlear implant recipients at that time were not being encouraged. Predisposing factors were also found including a prior history of meningitis, deformities of the cochlea and a certain surgical technique called a cochleostomy. Other risk factors include very young age, immunocompromise, and the presence of ventriculo-peritoneal shunts.4 Even deaf children without cochlear implants compared with the pediatric population as a whole also have an increased risk of getting meningitis.5 By contrast to this major concern, a 2005 study in the United Kingdom of 1851 children with cochlear implants found that none had contracted meningitis. Not only did the children in this study not have meningitis, early death was not found to be different between implanted children and the general population. The same study looked at 1779 adults with cochlear implants. Five had contracted meningitis and three had died. Of the five, four of the cases, including the fatalities, had risk factors for meningitis unrelated to implantation. All-cause death risk in implanted adults was not higher, and, in fact, was significantly lower at some time points after implantation.6
The most common microorganism causing meningitis is and has been Streptococcus pneumoniae. Since a vaccine exists for the most common and most virulent strains (serotypes) of this bacteria, age-appropriate vaccination is a powerful weapon for the prevention of post-implantation meningitis.7 With the meningitis concern and evidence that vaccination can prevent meningitis, the conclusion is that all children who receive cochlear implants should be appropriately vaccinated. In addition, all children with cochlear implants should be monitored and treated promptly for any bacterial infections after receiving the implant.
Since middle ears infections are common in children, some pediatric cochlear implant patients do suffer ear infections. That seldom leads to complications extending to the cochlear implant but when the ear infection spreads around the implant site, antibiotic therapy directed to the specific organism that is recovered the site is effective without removing the implant. 8,9,10 Some centers have aggressively treated ear infections in children who have cochlear implants with intravenous antibiotics.11,12 Mastoiditis is more common after an ear infection in children with cochlear implants but published evidence shows that conservative management of middle ear infections using oral antibiotics early is effective. The recommendation is that children prone to middle ear infection receive middle ear ventilating tubes.13,14 Removal of the cochlear implant in the context of mastoiditis seems quite uncommon.15 A review of studies suggests that in the first couple of weeks after a cochlear implant surgery, especially children with a deformed inner ear are at increased risk of getting meningitis if a middle ear infection develops in that early period. Early treatment of ear infections with antibiotics and use of middle ear ventilating tubes in ear infection-prone children seems to ameliorate that risk.16
Known, then, is that the risk of getting meningitis in persons with cochlear implants, especially children, is increased largely from middle ear infections, especially from Streptococcus pneumoniae. This somewhat increased risk was established in 2002 by the above mentioned CDC and the Food and Drug Administration study of children in the USA with cochlear implants.17 A United Kingdom study, a more recent study from India, and a more recent Chinese study did not find an association.18,19,20 Over the last 20 years, a general consensus is that both clinical and laboratory animal research establish that pneumococcal meningitis risk is increased a bit by having a cochlear implant. Least-possible surgical trauma is thought to reduce the risk, called a soft round window membrane technique. By contrast, a large cochleostomy for cochlear implant insertion may be associated with increased risk. Because of the worry about meningitis risk, the current recommendation is that all cochlear implant recipients should be offered vaccination against Streptococcus pneumoniae.21 Animal studies suggest that vaccines are protective against meningitis when a cochlear implant is in place.22
The leading causes of bacterial meningitis in the United States include: Haemophilus influenzae, Neisseria meningitidis (causes meningococcal meningitis), Streptococcus pneumoniae (causes pneumococcal meningitis). These three are pathogens that affect only humans. They normally colonize the nasopharynx and may invade the blood stream to cause systemic infections and meningitis.23 People with cochlear implants are specifically at increased risk for Streptococcus pneumoniae meningitis which can cause middle ear infections and traverse along the cochlear implant cable into the inner ear and from there cause meningitis. Thus, the Centers for Disease Control and Prevention (CDC) has issued pneumococcal vaccination recommendations for all individuals with cochlear implants. The recommendation is that children who have cochlear implants or are candidates for cochlear implants should receive PCV13 (recommendations not-yet updated to PCV20). Normally, independent of getting a cochlear implant, those vaccines start in children as a series of 4 doses, one dose at each of these ages: 2 months, 4 months, 6 months, and 12 through 15 months.24 The standing recommendation is that for all infants and children receive the series of vaccines (see Table 2 in the CDC March 12, 2010 MMWR issue located at the above website for the number of doses and dosing schedule). Older children with cochlear implants (from age 2 years through age 5) should receive two doses of the PCV vaccine if they have not received any doses of PCV7 or PCV13 previously. These recommendations can be viewed in detail on the CDC website.25 In June 2021, Pfizer was licensed to distribute PCV20 which covers 7 more potentially lethal serotypes of Streptococcus pneumoniae than does the PCV13 vaccine. Studies show that the PCV20 has modestly better rates of protection against a wider range of Streptococcus pneumoniae infection and the CDC now, in general terms, recommends the PCV20 vaccine.26
There is no evidence that children or adults with cochlear implants are more likely to get meningococcal meningitis, caused by the bacterium Neisseria meningitides, than children without cochlear implants.27 The Haemophilus influenzae type b (Hib) vaccine is routinely recommended for children under 5 years of age. Adults and children older than age 5 are already immune to Hib. Thus, available information does not suggest that older children and adults with cochlear implants require the Hib vaccine. However, the Hib vaccine can be given to older children and adults who have never received it. Most children born after 1990 have received the Hib vaccine as infants.28
In summary, the risk of getting meningitis at present with a cochlear implant is very low. Current best evidence is that implantation of children earlier than 12 months of age provides best possible speech and language outcomes. Thus, the motivation to both protect against meningitis and to provide early cochlear implant surgery is high.29 Current evidence is that children in Seattle have a high rate of being fully vaccinated but some children with cochlear implants fail to get the PPSV23 that is supposed to be administered after age 24 months for cochlear implant recipients.30 Studies of the current risk of getting meningitis after a cochlear implant seem not to be present but a 2011 study suggested that the rate of getting meningitis now was diminishing.31 A 2019 study of 200 children who were otitis media-prone in India did not find meningitis in any cases in 5 years post surgery.32 Thus, getting a cochlear implant appears to be very safe, especially if vaccinated against Streptococcus pneumoniae.
1 Reefhuis J, Honein MA, Whitney CG, Chamany S, Mann EA, Biernath KR, Broder K, Manning S, Avashia S, Victor M, Costa P, Devine O, Graham A, Boyle C. Risk of bacterial meningitis in children with cochlear implants. N Engl J Med. 2003 Jul 31;349(5):435-45. doi: 10.1056/NEJMoa031101. PMID: 12890842.
2 Cohen NL, Hirsch BE. Current status of bacterial meningitis after cochlear implantation. Otol Neurotol. 2010 Oct;31(8):1325-8. doi: 10.1097/MAO.0b013e3181f2ed06. PMID: 20818287.
3 Wei BP, Robins-Browne RM, Shepherd RK, Clark GM, O’Leary SJ. Can we prevent cochlear implant recipients from developing pneumococcal meningitis? Clin Infect Dis. 2008 Jan 1;46(1):e1-7. doi: 10.1086/524083. PMID: 18171202.
4 Cohen NL, Hirsch BE. Current status of bacterial meningitis after cochlear implantation. Otol Neurotol. 2010 Oct;31(8):1325-8. doi: 10.1097/MAO.0b013e3181f2ed06. PMID: 20818287.
6 Summerfield AQ, Cirstea SE, Roberts KL, Barton GR, Graham JM, O’Donoghue GM. Incidence of meningitis and of death from all causes among users of cochlear implants in the United Kingdom. J Public Health (Oxf). 2005 Mar;27(1):55-61. doi: 10.1093/pubmed/fdh188. Epub 2004 Nov 25. PMID: 15564280.
8 Vila PM, Ghogomu NT, Odom-John AR, Hullar TE, Hirose K. Infectious complications of pediatric cochlear implants are highly influenced by otitis media. Int J Pediatr Otorhinolaryngol. 2017 Jun;97:76-82. doi: 10.1016/j.ijporl.2017.02.026. Epub 2017 Mar 12. PMID: 28483256; PMCID: PMC6198317.
9 Raveh E, Ulanovski D, Attias J, Shkedy Y, Sokolov M. Acute mastoiditis in children with a cochlear implant. Int J Pediatr Otorhinolaryngol. 2016 Feb;81:80-3. doi: 10.1016/j.ijporl.2015.12.016. Epub 2015 Dec 31. PMID: 26810295.
10 Hoberg S, Danstrup C, Laursen B, Petersen NK, Udholm N, Kamarauskas GA, Ovesen T. Characteristics of CI children with complicated middle ear infections. Cochlear Implants Int. 2017 May;18(3):136-142. doi: 10.1080/14670100.2017.1289298. Epub 2017 Feb 24. PMID: 28235386.
12 Luntz M, Teszler CB, Shpak T. Cochlear implantation in children with otitis media: second stage of a long-term prospective study. Int J Pediatr Otorhinolaryngol. 2004 Mar;68(3):273-80. doi: 10.1016/j.ijporl.2003.10.001. PMID: 15129937.
13 Luntz M, Hodges AV, Balkany T, Dolan-Ash S, Schloffman J. Otitis media in children with cochlear implants. Laryngoscope. 1996 Nov;106(11):1403-5. doi: 10.1097/00005537-199611000-00018. PMID: 8914909.
14 Osborn HA, Cushing SL, Gordon KA, James AL, Papsin BC. The management of acute mastoiditis in children with cochlear implants: saving the device. Cochlear Implants Int. 2013 Nov;14(5):252-6. doi: 10.1179/1754762813Y.0000000049. Epub 2013 Aug 30. PMID: 23998418.
15 Zawawi F, Cardona I, Akinpelu OV, Daniel SJ. Acute mastoiditis in children with cochlear implants: is explantation required? Otolaryngol Head Neck Surg. 2014 Sep;151(3):394-8. doi: 10.1177/0194599814536686. Epub 2014 Jun 4. PMID: 24898070.
18 Summerfield AQ, Cirstea SE, Roberts KL, Barton GR, Graham JM, O’Donoghue GM. Incidence of meningitis and of death from all causes among users of cochlear implants in the United Kingdom. J Public Health (Oxf). 2005 Mar;27(1):55-61. doi: 10.1093/pubmed/fdh188. Epub 2004 Nov 25. PMID: 15564280.
19 Qiu J, Chen Y, Tan P, Chen J, Han Y, Gao L, Lu Y, Du B. Complications and clinical analysis of 416 consecutive cochlear implantations. Int J Pediatr Otorhinolaryngol. 2011 Sep;75(9):1143-6. doi: 10.1016/j.ijporl.2011.06.006. Epub 2011 Jul 8. PMID: 21741711.
20 Alzhrani F, Alahmari MS, Al Jabr IK, Garadat SN, Hagr AA. Cochlear Implantation in Children with Otitis Media. Indian J Otolaryngol Head Neck Surg. 2019 Nov;71(Suppl 2):1266-1271. doi: 10.1007/s12070-018-1301-z. Epub 2018 Mar 17. PMID: 31750162; PMCID: PMC6841993.
21 Wei BP, Robins-Browne RM, Shepherd RK, Clark GM, O’Leary SJ. Can we prevent cochlear implant recipients from developing pneumococcal meningitis? Clin Infect Dis. 2008 Jan 1;46(1):e1-7. doi: 10.1086/524083. PMID: 18171202.
22 Wei BP, Robins-Browne RM, Shepherd RK, Azzopardi K, Clark GM, O’Leary SJ. Assessment of the protective effect of pneumococcal vaccination in preventing meningitis after cochlear implantation. Arch Otolaryngol Head Neck Surg. 2007 Oct;133(10):987-94. doi: 10.1001/archotol.133.10.987. PMID: 17938321.
23 Tsang RSW. A Narrative Review of the Molecular Epidemiology and Laboratory Surveillance of Vaccine Preventable Bacterial Meningitis Agents: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae and Streptococcus agalactiae. Microorganisms. 2021 Feb 22;9(2):449. doi: 10.3390/microorganisms9020449. PMID: 33671611; PMCID: PMC7926440.
31 Lalwani AK, Cohen NL. Does meningitis after cochlear implantation remain a concern in 2011? Otol Neurotol. 2012 Jan;33(1):93-5. doi: 10.1097/MAO.0b013e31823dbb08. PMID: 22143298.
32 Alzhrani F, Alahmari MS, Al Jabr IK, Garadat SN, Hagr AA. Cochlear Implantation in Children with Otitis Media. Indian J Otolaryngol Head Neck Surg. 2019 Nov;71(Suppl 2):1266-1271. doi: 10.1007/s12070-018-1301-z. Epub 2018 Mar 17. PMID: 31750162; PMCID: PMC6841993.