Varicella zoster virus (VZV) infection of the central nervous system (CNS) is relatively uncommon. Diagnostic tests historically utilized culture, serologies, and targeted PCR methods. In April 2016, our institution began using the BioFire FilmArray meningitis/encephalitis (BFME) panel for cerebrospinal fluid (CSF) specimen analysis. We hypothesized that the diagnosis of VZV CNS infection increased at our institution with the implementation of this diagnostic panel.
We conducted chart reviews of patients from two time periods. In the first period, April 2013-March 2016, BFME was not available for CSF analysis (Pre-BFME period). We reviewed all positive CSF VZV PCR results during this period. Medical charts of these patients were reviewed for epidemiology, clinical presentation, treatment course and outcome. In the second period, April 2016-March 2018, BFME was performed on all CSF specimens obtained by lumbar puncture (BFME period). Patients with a positive VZV result on BFME underwent similar chart review.
In the three-year Pre-BFME period, 292 VZV PCR tests were performed. Six patients were diagnosed with VZV CNS infection; median age 61 years. Five of the six patients (83%) had cutaneous zoster. All six patients received antiviral therapy. Five of the six patients clinically improved; one patient with VZV encephalitis died. In the two-year BFME period, 1113 CSF samples were evaluated, and 18 of these were positive for VZV (1.6%); median age 55 years. Only seven of the 18 (39%) had cutaneous zoster at the time of hospitalization. All 18 received antiviral therapy with clinical improvement.
Prior to implementation of the BFME panel at our institution, VZV CNS infection was rarely diagnosed. Diagnosis at that time relied on physicians’ requests for a targeted CSF VZV PCR. The majority of the patients during that period had a concurrent zoster rash. In a shorter period utilizing syndromic testing (BFME) on CSF specimens, we diagnosed three times as many cases of VZV CNS disease. Only a minority of these patients presented with a concurrent zoster rash. The use of syndromic testing of CSF will likely identify more cases of VZV CNS disease.
B. Hess, None
J. DeSimone Jr., None