Comparison of bedside inoculation of culture media with conventional cerebrospinal fluid culture method in patients with bacterial meningitis

Abstract

Background: The yield of bacterial cultures from cerebrospinal fluid (CSF) at Kenyatta National Hospital (KNH) is very low. Bedside inoculation of culture media with CSF may improve yields.

Objective: To compare the culture yield of CSF inoculated onto culture medium at the bedside to that of CSF inoculated onto culture medium in the microbiology laboratory.

Design: Cross-sectional comparative study.

Setting: Accident and Emergency Department and medical wards at Kenyatta National Hospital.

Subjects: Cerebrospinal fluid from patients at KNH with a clinical diagnosis of acute meningitis.

Results: Two hundred and twenty CSF specimens were obtained during a four month period. S. pneumaniae was isolated from 24 CSF samples and H. influenzae from one. Bacterial cultures were positive in 25 (11.4%, 95% CI 7.0-15.6%) samples inoculated at the bedside and 23 (10.5%, 95% CI 6.5-14.5%) samples inoculated at the laboratory. Bacteria were isolated 5 hours earlier in samples inoculated at the bedside (95% CI 4.34-6.86 hrs, p < 0.05). Four per cent of S. pneumaniae isolates were resistant to crystalline penicillin.

Conclusion: There was no significant difference in culture yield after bedside inoculation of culture media with CSF compared to traditional CSF culture method. Bedside inoculation of culture media with CSF resulted in faster time to positive culture.