Herpes Zoster Not Linked to a Higher Risk of Dementia Diagnosis

Pavankumar Kamat


March 02, 2022


  • Herpes zoster (HZ) infection was not associated with an increased risk of dementia diagnosis.

Why This Matters

  • A better understanding of the complex relationships between infection, immune system modulation, and chronic disease risk may aid the identification of susceptible individuals and the development of interventional strategies.

Study Design

  • A historical cohort study used data from the Clinical Practice Research Datalink (CPRD), UK (2000-2017).

  • 177,144 patients with HZ (age, ≥40 years) and 706,901 matched participants without HZ were included.

  • Median follow-up duration was 4.6 years

  • Primary outcome: incident all-cause dementia.

  • Secondary outcomes: dementia subtypes (Alzheimer’s disease [AD], vascular dementia, other specified dementia, and mixed/unspecified dementia).

  • Funding: None disclosed.

Key Results

  • The overall incidence rate of dementia was 5.58 (95% CI 5.51 to 5.65)/1000 person-years.

  • After adjustment for confounders, HZ was associated with a marginal reduction in the risk of dementia diagnosis (adjusted HR [aHR] 0.92; 95% CI 0.89 to 0.95), which was predominantly reported in patients with frailty and women.

  • HZ was not associated with an increased risk of dementia diagnosis in patients who were fit (aHR 0.97; 95% CI 0.92 to 1.02).

  • No association was observed between HZ and (aHR; 95% CI):

    • composite outcome of dementia or death (1.00; 0.99 to 1.02);

    • AD (0.94; 0.89 to 1.00);

    • vascular dementia (0.95; 0.90 to 1.02); and

    • other specified dementia subtypes (0.91; 0.77 to 1.07).

  • A marginal protective association was seen between HZ and mixed or unspecified dementia (aHR 0.88; 95% CI 0.83 to 0.92).


  • Risk of residual confounding.

Warren-Gash C, Williamson E, Shiekh SI, Borjas-Howard J, Pearce N, Breuer JM, Smeeth L. No evidence that herpes zoster is associated with increased risk of dementia diagnosis. Ann Clin Transl Neurol. 2022 Feb 16 [Epub ahead of print]. doi: 10.1002/acn3.51525. PMID: 35170873 View Full Text.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.