Atypical varicella zoster virus CNS infections: Diagnostic challenges and the role of multiplex PCR

Varicella zoster virus (VZV) can cause central nervous system (CNS) infections, including meningitis and meningoencephalitis. This study describes the clinical and laboratory characteristics of VZV CNS infections diagnosed by multiplex PCR, a diagnostic tool with increasing global availability.

This retrospective study was conducted at a tertiary hospital in Taiwan and included patients diagnosed with VZV meningitis or meningoencephalitis from May 2023 to May 2024. VZV DNA in cerebrospinal fluid was detected using multiplex PCR. Data were collected from electronic health records, and statistical analysis was performed using SPSS 20.0.

Fifteen patients were included, 7 with meningoencephalitis and 7 with meningitis. Shingles was present in 66.7 % of patients. Notably, 40 % of patients had no pleocytosis in cerebrospinal fluid. The median hospital stay was significantly longer for meningoencephalitis patients (25.8 days) compared to meningitis patients (11.9 days, p = 0.018).

This study highlights the prevalence of atypical presentations in VZV CNS infections, including cases without cutaneous manifestations and those lacking cerebrospinal fluid pleocytosis. The findings underscore the critical role of multiplex PCR in diagnosing VZV meningitis and meningoencephalitis, particularly in cases with atypical presentations. The study also reveals the more severe nature of meningoencephalitis, as evidenced by longer hospital stays. These results challenge traditional diagnostic approaches and emphasize the need for a high index of suspicion for VZV in all cases of suspected viral CNS infection, regardless of initial clinical or cerebrospinal fluid findings.