Can we refute a role for infections in Alzheimer's disease pathogenesis?

Alzheimers Dement. 2026 Mar;22(3):e71288. doi: 10.1002/alz.71288.

Abstract

While a growing body of literature suggests a role for infections in Alzheimer's disease (AD), microbial contributions to AD remains a contentious topic, in part due to challenges in reconciling the positive evidence with studies reporting null findings. Here, we examine the evidence that argues against a role for infections in AD, while offering mechanistic hypotheses that may account for both the negative and positive findings, including dysregulated host immunity and gene-environment interactions of AD-associated genes.

Keywords: APOE; HSV‐1; amyloid beta; apolipoprotein E; infection; microglia; virus.

Publication types

  • Review

MeSH terms

  • Alzheimer Disease* / etiology
  • Alzheimer Disease* / genetics
  • Alzheimer Disease* / immunology
  • Alzheimer Disease* / microbiology
  • Alzheimer Disease* / virology
  • Animals
  • Gene-Environment Interaction
  • Humans
  • Infections* / complications