Associations of Infectious Agents with Alzheimer's Disease: A Systematic Review and Meta-Analysis.
Level 4 - case-series / case-control
Systematic review and meta-analysis of case-control studies
PubMed 32280095 · doi:10.3233/JAD-191337
What was done
A systematic review and random-effects meta-analysis was conducted across PubMed, Embase, and the Cochrane Library to assess associations between infectious agents and the risk of Alzheimer's disease. Publication bias was evaluated using funnel plots.
What was found
Fifty-one studies were included in the systematic review, of which 47 case-control studies with 108,723 participants and 4,039 Alzheimer's disease cases were meta-analyzed. Significant associations with higher odds of Alzheimer's disease were found for Chlamydia pneumoniae (OR 4.39, 95% CI 1.81-10.67; I2 = 68%), Human herpes virus-6 (OR 3.97, 95% CI 2.04-7.75; I2 = 0%), Epstein-Barr virus (OR 1.45, 95% CI 1.00-2.08; I2 = 0%), Herpes simplex virus-1 (OR 1.34, 95% CI 1.02-1.75; I2 = 0%), and the Herpesviridae family overall (OR 1.41, 95% CI 1.15-1.74; I2 = 12%). Funnel plots showed no significant publication bias.
Why it matters
This meta-analysis synthesizes observational evidence linking specific bacterial and herpesvirus infections to Alzheimer's disease risk. It provides a quantitative foundation for evaluating antimicrobial or antiviral strategies in dementia prevention.
Limits
The findings are derived entirely from case-control studies, precluding determinations of temporality or causality. Substantial heterogeneity was observed for Chlamydia pneumoniae (I2 = 68%). Confounding factors and diagnostic criteria in individual studies are not detailed in the abstract.
Cited by
- supports Herpesvirus infection is associated with an increased risk of developing Alzheimer's disease.