Varicella zoster virus infection and reactivation in a psychiatric ward during the COVID-19 pandemic: a case series analysis

Severe mental illness (SMI) may increase susceptibility to varicella zoster virus (VZV), but VZV epidemiology in psychiatric wards is poorly described.We reviewed 54 women with SMI in a closed 50-bed psychiatric ward (July 2021-December 2024) and identified 3 varicella and 2 herpes zoster cases during April-October 2023.The varicella attack rate among exposed susceptibles was 6.38%, and herpes zoster incidence was 12.41 per 1,000 person-years.All case patients had received coronavirus disease 2019 vaccination and had prior severe acute respiratory syndrome coronavirus 2 infection.These findings highlight infection-control challenges, immune vulnerabilities, and prevention gaps in long-term psychiatric settings.