Epidemiology of Herpes Zoster in the pre-vaccination era: establishing the baseline for vaccination programme's impact in Spain

Abstract

A nationwide retrospective study based on the Spanish National Health System Hospital Discharge Database analysed 65,401 herpes zoster (HZ)-related hospitalisations between 1998 and 2018. The mean annual hospitalisation rate was 6.75 per 100,000 population, with a significant increasing trend over time, particularly in individuals aged ≥65 years. Male sex and immunocompromising conditions were associated with higher severity. Leukaemia/lymphoma and solid malignant neoplasm showed the highest adjusted risk ratios for readmission and mortality, while HIV infection was also independently associated with fatal outcome. This study establishes a national baseline prior to the progressive implementation of recombinant zoster vaccination in Spain, providing essential epidemiological data for future effectiveness assessments and public health planning.