Diagnostic comparison of microbial culture and polymerase chain reaction for the diagnosis of bacterial meningitis in a tertiary hospital, North West Ethiopia

Background

Bacterial meningitis (BM) represents the most severe variant of meningitis, with a mortality rate that may reach up to 100% in the absence of appropriate treatment. The success of therapeutic interventions is depends upon prompt and precise diagnostic evaluations. However, there exists a significant deficiency in the literature regarding the diagnostic efficacy within the Ethiopian context. Consequently, this study aims to evaluate and compare the diagnostic precision of microbial culture and polymerase chain reaction (PCR) methodologies in individuals with suspected meningitis in Northwest Ethiopia.

Methods

Cerebrospinal fluid (CSF) samples were procured from 400 patients who were clinically suspected of having meningitis and were admitted to the University of Gondar Specialized Hospital (UoGSH), located in Northwest Ethiopia. Real-time PCR, microbial culture, Gram staining, and cell enumeration were conducted at both the UoGSH laboratory and the Armauer Hansen Research Institute in Addis Ababa.

Results

Of the total patients enrolled in the study, 58% were male. Clinical manifestations such as fever, headache, and neck stiffness were reported in 94%, 90%, and 81% of the patients, respectively, whereas altered consciousness was recorded in 37% of the cohort. The real-time PCR methodology identified 38 patients (10%) as positive for meningitis, in contrast to microbial culture, which detected only 10 (3%) of these positive cases. The two diagnostic modalities exhibited a correlation coefficient of 0.4 (p < 0.05).

Conclusion

The traditional microbiological culture technique, in conjunction with Gram staining, was found to have a limited sensitivity in identifying bacterial meningitis compared with the real-time PCR methodology. Consequently, the integration of molecular approaches with higher sensitivity, such as real-time PCR, facilitates prompt diagnosis and precise treatment, while simultaneously sustaining the overarching meningitis surveillance framework.