Methods: A case-control study was conducted within the Kaiser Permanente Northern California (KPNC) patient population to evaluate the association of prior head injury (HI) or head or spine surgery (H/SS) with pneumococcal meningitis. Cases were pneumococcal meningitis patients ≥18 years of age diagnosed from January 1, 2008 through October 31, 2017. Controls were individually matched 2:1 by age, sex, KPNC facility and membership length. A blinded chart review was done to identify history of HI and H/SS. Analyses were performed using conditional logistic regression.
Results: Eighty-four patients were found to have pneumococcal meningitis and were matched with 168 controls. Fifteen of the 84 cases (17.9%) and 6 of the 168 controls (3.6%) had prior HI or H/SS. Case histories included concussion (n=3), mastoidectomy (n=2), nasal surgery (n=3), neurosurgery (n=3) and spine surgery (n=5). One case was noted to have two surgical histories. Ten of the 15 cases with HI or H/SS (66.7%) had not received pneumococcal vaccine. Cases had 5.0 times higher odds of having a history of HI or H/SS (95% confidence interval (CI) 1.9-12.9). These odds remained significantly elevated for H/SS only (odds ratio (OR) 10.0, 95% CI 1.2 – 85.6), but not for HI (OR 3.0, 95% CI 0.5 – 18.0). As no skull fractures were detected, HI consisted of concussions only.
Conclusion: Prior HI or H/SS significantly increased the odds for pneumococcal meningitis. Surveillance data from the Centers of Disease Control and Prevention indicate that 60-75% of invasive pneumococcal disease in adults is due to serotypes included in the pneumococcal vaccines. Given the number of unvaccinated cases, some of these cases may have been vaccine preventable. Such patients may benefit from pneumococcal immunization to reduce the risk of pneumococcal meningitis.
K. Winter, None
K. Harriman, None
C. Glaser, None