Factors associated with the occurrence of hearing loss after pneumococcal meningitis

On the basis of a nationwide registration during a 5-year period (1999-2003), the frequency and severity of hearing loss was investigated retrospectively in 343 consecutive Danish patients who survived pneumococcal meningitis, to identify important risk factors (including the pneumococcal serotype) for development of hearing loss.

Results of blood and cerebrospinal fluid (CSF) biochemistry, bacterial serotyping, follow-up audiological examinations, and medical records were collected, and disease-related risk factors for hearing loss were identified. The mean pure-tone hearing threshold levels were compared with normative data.

Of 240 patients examined by use of audiometry, 129 (54%) had a hearing deficit, and 50 (39%) of these 129 patients were not suspected of hearing loss at discharge from hospital. Of the 240 patients, 16 (7%) had profound unilateral hearing loss, and another 16 (7%) had bilateral profound hearing loss. Significant risk factors for hearing loss were advanced age, the presence of comorbidity, severity of meningitis, a low CSF glucose level, a high CSF protein level, and a certain pneumococcal serotype (P < .05). By applying multivariate logistic regression analysis, we found that advanced age, female sex, and a certain serotype were significant risk factors, because fewer patients with serotype 6B had hearing loss than did patients with serotype 12F (P = .03), which was the most commonly occurring serotype.

Hearing loss is common after pneumococcal meningitis, and audiometry should be performed on all those who survive pneumococcal meningitis. Important risk factors for hearing loss are advanced age, female sex, severity of meningitis, and bacterial serotype.