Case report: Varicella-zoster virus encephalitis a new type of "ICU-acquired infection"?

Purpose: Varicella-zoster virus (VZV) can cause a wide range of neurological complications, including meningoencephalitis, upon reactivation. The objective of this report is to alert physicians of the possibility of VZV recurrence with meningoencephalitis occurring during hospitalization in an intensive care unit (ICU) setting. Material and methods: Clinical observation of one patient. Case report: A 65 years old man was admitted to the ICU for subarachnoid hemorrhage. Although the initial treatment plan proved successful, the patient experienced numerous, mainly septic, complications. After stabilization, neurological impairment was observed with spontaneous eye opening without contact and no motor response, apart from sedation. Cerebrospinal fluid (CSF) PCR assay was positive for VZV. Intravenous acyclovir was administered for 14 days. Neurological status gradually improved with the patient showing eye and mouth opening on request as well as recovery of basic speech with one-word responses. Quantitative PCR assays showed significant decrease of VZV. EEG improved after treatment to show clear reactivity, but the abnormalities at baseline were non-specific of VZV meningoencephalitis. No new focal lesion was identified on MRI that could be linked to VZV meningoencephalitis. The patient recovered from VZV meningoencephalitis, but he finally died 44 days later, following cardiac arrest, with no reactivation of VZV infection. Conclusion: VZV meningoencephalitis may occur during hospitalization, especially during prolonged ICU stay which may be due to reactivation associated with sepsis-induced immunosuppression. It might be underestimated as MRI and EEG seem poorly contributive to the diagnosis, so CSF PCR analysis is the cornerstone exploration.