A comprehensive, updated systematic review and meta‐analysis of epidemiologic evidence on the connection between herpes zoster infection and the risk of stroke

Abstract Stroke is a common worldwide cause of death and disability, resulting from an obstruction or reduction in blood flow to the brain. Research has demonstrated that systemic infection such as herpes zoster (HZ) / ophthalmicus herpes zoster (HZO) can potentially trigger stroke. This study includes an updated systematic review and meta‐analysis of the epidemiologic data on the connection between HZ/HZO infection and the risk of stroke. A meticulous search of different database yielded 905 studies. Furthermore, an additional 14 studies from a previous meta‐analysis were incorporated. Eligible studies underwent rigorous screening, resulting in 18 papers. Statistical analyses, including random/fixed effects models and subgroup analyses, were conducted to assess pooled relative risk (RR) and heterogeneity. The meta‐analysis consisted of 5,505,885 participants and found a statistically significant association between HZ infection and the risk of stroke (pooled RR = 1.22, 95% confidence interval [CI] 1.12–1.34). The HZO infection showed a significantly higher overall pooled RR of 1.71 (95% CI 1.06–2.75), indicating a strong connection with the risk of stroke. Subgroup analysis revealed that the odds ratio might play a significant role in causing heterogeneity. Time since infection emerged as a crucial factor, with heightened stroke risk in the initial year post‐HZ/HZO exposure, followed by a decline after the first year. Asian/Non‐Asian studies demonstrated varied results in HZ/HZO patients. Meta‐analysis reveals a significant HZ/HZO‐stroke link. Subgroups highlight varied risks and warrant extended Asian/non‐Asian patient investigation.