Hospitalizations of patients with herpes zoster in Poland during 2012-2021: A population-based study

Introduction: The varicella-zoster virus (VZV) is an infectious agent that causes both chickenpox and herpes zoster/shingles (HZ). This infection can take various clinical forms, result in permanent complications, and be a marker of immunosuppression, e.g. in the course of a neoplastic disease. The aim of this study is to analyze epidemiological trends in hospitalization and hospital mortality rate among HZ patients in Poland (2012-2021). Methods: Our study is a population-based, retrospective analysis of hospital discharge records of patients with HZ. Data were obtained from the National Institute of Public Health in Poland, and they covered the period from 2012 to 2021. All hospitalization records with primary or secondary ICD-10 B02 code diagnosis were included in the study. Results: We analyzed the total number of 23,432 hospital discharge records of HZ patients in 2012-2021. The study group consisted of 22,169 (94.6 %) hospitalization records of first-time diagnosis of HZ in hospitalized patients: 9,309 males (42 %) and 12,860 females (58 %). In this group, 70.3 % were patients over 60 years old. The mean and median age was 64 and 69 years, respectively. The mean annual first-time hospitalization rate for HZ was estimated to be 5.8 per 100,000 person-years (95 % CI: 4.8-6.7 per 100,000 person-years). The hospitalization rate for HZ was similar during 2012-2019. There was a significant decrease in hospitalizations in 2020-2021 in comparison with the previous years (R-2 = 0.42, p < 0.05). Women showed a higher hospitalization rate than men (p < 0.001). Urban residents had a higher hospitalization rate than rural residents (p < 0.001). In the analyzed period, 246 deaths were recorded (1.1 % of all hospitalized HZ patients) -119 males and 127 females. Conclusions: The HZ-related number of hospitalizations and mortality in Poland are relatively low, but HZ is still a significant health problem. Risk factors include female gender, older age and residence in urban areas.