Background: The syndromic approach for the diagnosis of Central Nervous System (CNS) infections enables the rapid detection of multiple pathogens in cerebrospinal fluid (CSF) specimens. The aim of the study was to evaluate the use of CSF pleocytosis as an indicator for the optimal utilization of BIOFIRE® FILMARRAY® Meningitis/Encephalitis (FA) panel.
Materials/methods: In the first period of the study (06.2018-05.2019), FA was performed only in children with suspected CNS infection and CSF pleocytosis >15 cells/mm3. In the second period (06.2019-11.2019) there was no cut-off and all CSF samples were tested with FA. Pathogen detection rate (%) was compared between children with CSF ≤15 or >15 cells/mm3, within two age groups (>3 or ≤ 3 months of age).
Results: A total of 170 children were included in the study with median age 2.5 months (IQR: 0.7-27). Pathogen detection rate (%) with FA in the first and second study period was 46.3% (37/80) and 21.1% (19/90), respectively (P-value: 0.001). In CSF samples without pleocytosis which were tested with FA, the pathogen detection rate was 15.3% (9/59). Enterovirus was detected in 5 CSF samples (6.7%), HHV-6 in 3 (5.1%) and parechovirus in 1 (1.7%). The median age of children without pleocytosis, but with a pathogen detected was 0.66 months (IQR:0.41-4.75). In children >3 months (n=68) with CSF ≤15 or >15 cells/mm3, a pathogen was detected in 2/15 (13.3%) and 26/53 (49.1%), respectively (P-value: 0.013). In children ≤3 months (n=102) with ≤15 or >15 cells/mm3, a pathogen was detected in 7/44 (15.9%) and 21/58 (36.2%) samples, respectively (P-value: 0.023). No difference in detection rate was found in newborns ≤1 month (n= 65) between CSF ≤15 or >15 cells/mm3, 6/29 (20.7%) and 9/36 (25%), respectively, (P-value: 0.682).
Conclusions: Absence of CSF pleocytosis does not exclude CNS infection, especially in infants less than 3 months of age and newborns.