J Prev Alzheimers Dis

Herpes zoster tied to increased dementia risk

April 23, 2025

Study details: This population-based study utilized a region-wide Italian registry to investigate the association between severe herpes zoster infection and dementia occurrence over a 23-year period. The study included individuals aged ≥50 who were hospitalized with zoster, and two comparison cohorts from the general and hospitalized populations without zoster.

Results: The study identified 132,968 individuals, including 12,088 with severe zoster. The adjusted sub-distributed hazard ratio of dementia was 1.13 (95% confidence interval [CI], 1.07-1.19) compared with the general population, and 1.08 (95% CI, 1.03-1.14) compared with the hospitalized population. The increased risk was significant across different strata, including sex, age groups, and follow-up periods.

Clinical impact: These findings underscore the importance of improving herpes zoster prevention and extending vaccination recommendations to younger age groups to mitigate the increased risk of dementia associated with severe zoster infection.

Source:

Blandi L, et al. (2025, April 12). J Prev Alzheimers Dis. Herpes zoster as risk factor for dementia: a matched cohort study over 20 years in a 10-million population in Italy. https://pubmed.ncbi.nlm.nih.gov/40222838/