Pseudomonas aeruginosa meningitis/ventriculitis in a UK tertiary referral hospital.

BACKGROUND: Pseudomonas aeruginosa is a rare cause of meningitis and ventriculitis but is generally associated with significant morbidity and mortality.

AIM: We sought to determine the epidemiology, risk factors and outcome of meningitis and ventriculitis due to P. aeruginosa at our institution in order to inform preventive strategies and treatment guidelines.

METHODS: Retrospective study of all patients with a positive cerebrospinal fluid (CSF) culture admitted to a tertiary care hospital over 18 years. Clinical details, demographic, microbiological and antibiotic data were obtained from laboratory and medical records.

RESULTS: Twenty-four episodes occurred in 21 patients over 18 years. Pyrexia (75%), fluctuating mental status (50%) and headache (41%) were the most frequent presenting symptoms. Nineteen of the 21 patients had previously undergone a neurosurgical procedure and seven had extra-ventricular devices in situ. Twelve (57%) patients had P. aeruginosa isolated from another site prior to their episode. Most (89%) CSF samples demonstrated a neutrophilia; the CSF protein, when measured, was raised in all cases. Gram-negative bacilli were visible on CSF microscopy in only three isolates. There were relatively low rates of resistance to most antimicrobials tested and combination treatment of intravenous with intrathecal antibiotics was often used. No patients died within 28 days.

CONCLUSION: Pseudomonas aeruginosa meningitis and ventriculitis are predominantly nosocomial and related to prior neurosurgery. It can be difficult to diagnose as CSF Gram-film and meningism are insensitive markers. Appropriate empirical treatment, neurosurgical prophylaxis and surveillance can aid in managing this infection.