Time to positive culture can differentiate post‐neurosurgical coagulase‐negative Staphylococci other than S epidermidis meningitis from contamination: A case‐control observational study

OBJECTIVE: To explore the characteristics of coagulase‐negative Staphylococci other than Staphylococci epidermidis (Nse‐CoNS) meningitis and to apply cerebrospinal fluid (CSF) times to positivity culture (TTPC) for the precise differentiation of meningitis from contamination. METHODS: We conducted a case‐control study to accomplish the following: First, we retrospectively reviewed records of post‐neurosurgical patients’ CSF that yielded Nse‐CoNS from January to October 2019 at the Beijing Tiantan Hospital; 17 clinical and 12 laboratory characteristics were reviewed. Second, we investigated the TTPC of the Nse‐CoNS, the cutoffs, and corresponding parameters to differentiate Nse‐CoNS meningitis from contamination. RESULTS: In this study, a total of 146 patients with Nse‐CoNS CSF culture positive were enrolled. The average TTPC in the Nse‐CoNS meningitis group was significantly shorter than in the contamination group (20.2 ± 5.0 hours and 30.2 ± 12.6 hours, respectively, P < .05). The area under curve (AUC) of the model was 0.802. A TTPC of 20.0 hours had 94.3% sensitivity and a negative value of 90.2% for predicting Nse‐CoNS meningitis. CONCLUSIONS: Nse‐CoNS meningitis often causes confusion in clinical diagnosis. In this study, we evaluated the clinical predictive factors of Nse‐CoNS meningitis and confirmed that the median TTPC in the Nse‐CoNS meningitis group was significantly shorter than in the contamination group. A TTPC shorter than 20.0 hours was associated with Nse‐CoNS meningitis, while a TTPC longer than 20.0 hours was associated with Nse‐CoNS contamination. This information will be helpful for the rapid diagnosis of Nse‐CoNS meningitis.