Impact of a 24/7 multiplex-PCR on the management of patients with confirmed viral meningitis

•± 50% of pleocytosis are infectious meningitis in emergency departments.•24/7 multiplex-PCR strategy has an impact on rate of hospitalization for patients with confirmed viral meningitis.•A CSF WBC threshold of 10 /mm3 is adapted for systematic triggering of multiplex-PCR in adults.Summary The relevance of syndromic multiplex-PCR for the etiological diagnosis of meningitis or meningoencephalitis is still a matter of debate. Here, we studied the impact of a 24/7 multiplex-PCR on the management of patients consulting in the emergency department for suspicion of community-acquired meningitis. We conducted a single-center retrospective study at the Emergency department of Lariboisière University Hospital (Paris, France) including all patients suspected of meningitis. During period 1 (April 2014-March 2017), the molecular assays used for the detection of infectious agents in the cerebrospinal fluid (CSF) were performed during the daytime. During period 2 (April 2017-March 2019), multiplex-PCR (BioFire® Filmarray® Meningitis/Encephalitis Panel [ME], bioMérieux) was performed 24/7. During the periods 1 and 2, 4 100 and 3 574 patients were included and 284 (6.9%) and 308 (8.6%) meningitis were diagnosed, respectively. During the periods 1 and 2, the most common causes of meningitis were enterovirus (23.9% and 29.5%), varicella zoster virus (10.2% and 6.8%) and herpes simplex virus-2 (4.2% and 8.1%). For patients with confirmed viral meningitis, a significant decrease was found between period 1 and period 2, respectively for the rate of hospitalization (73.9% vs 42.0%; p