Bacterial meningitis among cochlear implant recipients--Canada, 2002.

INTRODUCTION

In July 2002, a cluster of bacterial meningitis (BM) cases was identified among European cochlear implant recipients (CIRs), prompting Health Canada to conduct a retrospective cohort study to determine the rate of BM infection among Canadian CIRs and to identify risk factors for acquiring BM.

METHODS

A survey was mailed to 1,432 Canadian CIRs who had received implants during January 1995-July 2002 to assess occurrence of postimplant BM infection. Data collection included demographics, episodes of meningitis, and vaccination status.

RESULTS

A total of 1,024 (72%) surveys were completed. Median age of CIRs at implantation was 16 years (range: 7 months-81 years). Five (0.5%) cases of BM infection were reported (two pneumococcal, one meningococcal, and two of unknown etiology); one CIR died. Four cases occurred among children aged <18 years. Time between implantation and BM infection varied (range: 7 months-7.7 years; median: 11 months). The rate of BM infection per 1,000 person-years was 0.7 among CIRs aged > or =18 years and 2.9 among those aged <18 years. The proportion of CIRs vaccinated against pneumococcal and meningococcal disease was low (46% and 41%, respectively). Preimplant meningitis was identified as a risk factor for postimplant BM (p = 0.002). No other risk factors evaluated were associated with an increased risk for BM infection.

CONCLUSION

CIRs have a high rate of postimplant BM infection. Preimplant BM infection was identified as a risk factor. Cases of BM infection might have been prevented through vaccination.