Yuji Maruo, Hiroki Shimomura, Satoshi Hirakawa, Yoshinori Omori, Atsuo Togashi, Nobuhisa Ishiguro, Kenichi Takano, Satoshi Yakuwa, Bin Chang, Shigeru Suga
Although pneumococcal conjugate vaccines have reduced invasive pneumococcal disease (IPD) in children, infections caused by non-vaccine serotypes remain a significant clinical concern. Children with congenital inner ear malformations and cochlear implants (CIs) face an elevated risk of bacterial meningitis, due to potential abnormal communication between the inner ear and subarachnoid space. We report a case of pneumococcal meningitis caused by the non-vaccine serotype 34 in a child with bilateral CIs, who had completed the recommended pneumococcal vaccine schedule. A 2-year-old boy with bilateral congenital sensorineural hearing loss, secondary to a right common cavity and left cochlear hypoplasia type I, underwent bilateral cochlear implantation. Intraoperative cerebrospinal fluid (CSF) leakage was observed during both implantation procedures. His immunization history was up to date and included both the 13-valent and 20-valent pneumococcal conjugate vaccines (PCV13 and PCV20). He presented with fever, vomiting, and lethargy. CSF examination revealed marked neutrophilic pleocytosis, and a multiplex meningitis/encephalitis polymerase chain reaction assay detected Streptococcus pneumoniae. Blood and CSF cultures confirmed S. pneumoniae serotype 34. Following antimicrobial therapy, he recovered without neurological sequelae. However, recurrent bacterial meningitis two months later necessitated right CI explantation and contralateral device replacement. This case underscores that IPD caused by non-vaccine serotypes can still occur in children with congenital inner ear malformations and CIs who have completed the recommended pneumococcal vaccine schedule. Persistent anatomical susceptibility may drive recurrent meningitis, warranting careful long-term follow-up and the timely consideration of implant removal in cases of recurrent infection.