Evaluation of cerebrospinal fluid white blood cell count criteria for use of the BioFire® FilmArray® Meningitis/Encephalitis Panel in immunocompromised and nonimmunocompromised patients

Utilization of a Meningitis/Encephalitis PCR panel at the University Hospital Basel – a retrospective study to develop a diagnostic decision rule

“…In these studies, the authors showed a safe reduction in herpes virus testing using a cutoff of 10 × 10 6 CSF leukocytes pro liter in non-immunocompromised patients ( 23 , 25 ). Similarly, McCreery et al showed an effective and safe reduction of the ME panel use in non-immunocompromised adults with CSF leukocytes count <10 ×10 6 /l ( 24 ). Due to the reported ( 26 ) possibility of bacterial meningitis with normal cerebrospinal fluid leukocytes counts and presence of severely immunocompromised patients in our analysis, protein concentration in cerebrospinal fluid was included in our criteria.…”

“…These observations warrant a more rational use of this panel to reduce unnecessary tests and costs. Development of management and testing guidelines (21,22) and education of clinicians are essential, but, as described in previous studies (23,24), not sufficient to reach this goal. Therefore, the use of clinical decision support may represent a good option to improve testing behavior, identifying the patient population that may benefit the most from this test and avoiding unnecessary investigations (24).…”

“…Development of management and testing guidelines (21,22) and education of clinicians are essential, but, as described in previous studies (23,24), not sufficient to reach this goal. Therefore, the use of clinical decision support may represent a good option to improve testing behavior, identifying the patient population that may benefit the most from this test and avoiding unnecessary investigations (24). In our analysis, we confirmed a widespread, indiscriminate use of the ME panel probably as a consequence of a significant overestimation of an infectious etiology underlying the presentation of the respective patients, which may be identified by the ME panel.…”

“…For these reasons, we developed a simple decision rule based on leukocytes and protein concentration in CSF to promote a rational use of the ME panel and provide clinical decision support in patients with suspected CNS infection. These criteria were based on previous studies using similar strategies to safely reduce the ME panel use or CSF herpes virus testing (23)(24)(25). In these studies, the authors showed a safe reduction in herpes virus testing using a cutoff of 10 × 10 6 CSF leukocytes pro liter in non-immunocompromised patients (23,25).…”

Cerebrospinal fluid analysis in emergency patients with suspected infection of the central nervous system

“…Studies with such a pre-selection (e.g., positive gram stain, detection of leukocytes and/ or bacteria, urgent clinical suspicion) show relatively high detection rates of pathogens in comparison to other studies [20]. Use of the array in patients with no suspicion for a CNS infection or in samples with normal CSF cell count could be avoided [21,22]. Exceptions might be CSF samples from patients with suspected sterile acute bacterial meningitis (in such cases, the CSF/serum glucose ratio is usually low) or patients with suspected early HSV encephalitis (as studies showed that 20% of patients with HSV encephalitis present with an initially normocytic CSF [23]).…”