Clinical and Laboratory Profiles, Time to Presentation, and Antibacterial Therapy in Children with Aseptic Meningitis: A Comparison of Confirmed Enteroviral and Unidentified-Etiology Cases

Background/Objectives: Pediatric aseptic meningitis remains diagnostically challenging because early manifestations may be incomplete, cerebrospinal fluid (CSF) findings vary with disease stage, and etiologic confirmation is not always available. This study compared hospitalized children with PCR-confirmed enteroviral meningitis and meningitis of unidentified etiology, focusing on presentation timing, CSF patterns, and antibacterial therapy. Methods: This single-center retrospective observational study included 87 pediatric patients hospitalized with aseptic meningitis or meningoencephalitis. Patients were classified into a PCR-confirmed enteroviral group (EV+, n = 58) and an unidentified-etiology group (n = 29). Clinical characteristics, time from symptom onset to admission, meningeal signs, peripheral blood inflammatory markers, CSF parameters, associations among CSF variables, and antibacterial therapy were analyzed. Results: A marked summer pattern was observed, with 73 of 87 cases occurring from June to August. Most patients were admitted 2–5 days after symptom onset. Compared with the unidentified-etiology group, EV+ patients had lower body temperature, total leukocyte count, neutrophil percentage, and absolute neutrophil count, and a higher lymphocyte percentage. CSF cell count, protein, glucose, and chloride did not differ significantly between groups. In both groups, CSF cell count correlated positively with protein concentration. CSF glucose was unrelated to inflammatory CSF markers in the EV+ group but correlated negatively with CSF cell count and protein in the unidentified-etiology group. Antibacterial therapy was more frequent in the unidentified-etiology group. Conclusions: Combining clinical presentation, peripheral blood markers, CSF relationships, and molecular findings may improve diagnostic confidence and support more appropriate antibacterial treatment decisions in children with suspected aseptic meningitis.