Large viral meningoencephalitis CSF serologic panel lacks utility in clinical decisions and outcomes.

Introduction: Accurate diagnosis of viral meningoencephalitis (VMe) and identification of the etiologic agent has clinical importance and large serology panels are available to aid in the detection of several viral pathogens. However, such panels are often send-out testing, with prolonged time to results, thus impacting the actionability of test results. We hypothesized these panels may not contribute to patient care and lack clinical utility.

Methods: A retrospective review of all VMe CSF serology panels ordered at one pediatric (n = 53; 2017-2019) and two adult (n = 200; 2019-2020) tertiary care hospitals was performed to assess test clinical utility. Panels included serology for: Adenovirus, coxsackie and echoviruses, influenza, measles, lymphocytic choriomeningitis virus, herpes simplex virus, mumps, varicella zoster, encephalitis viruses. Clinical data collected included diagnostic test results, symptoms, comorbidities, and interventions.

Results: In 129/200 (64.5 %) of adult cases and 37/53 (69.8 %) of pediatric cases CSF had a WBC less than 5 cells/mm. In total, 127 (63.5 %, 127/200) adult panels had at least one positive target with 49 panels having more than one positive (38.6 %, 49/127). In 99.5 % of adult and 100 % of pediatric cases there was no change to decisions regarding starting, discontinuing, continuing, or changing antimicrobial therapy based on panel results. In no cases were potentially immunosuppressive therapies like steroid or IVIG administration delayed while awaiting the results of the panel.

Conclusions: While all patients presented with neurologic symptoms, poor pre-screening for CNS inflammation using CSF WBC analysis likely contributed to poor clinical utility of the VMe panels. Large CSF serologic panels for VMe did not contribute to or add value to clinical decision making in our cohort.