Herpes Viruses Increase the Risk of Alzheimer's Disease: A Meta-Analysis.

The role of infectious agents in the development of AD has long been debated, in particular, the herpesviridae family. We therefore conducted a meta-analysis to quantitatively assess all published data to establish whether there is an association. We identified studies that looked for the presence of viral DNA in the brain and/or antibody seropositivity in people with AD from four electronic databases. 35 studies met our inclusion criteria (AD cases = 1294; controls = 3059). There was an increased risk for AD when herpesviridae is present in the brain compared to controls [OR 1.38; 95% CI 1.14-1.66]. Sub-analysis showed that APOE ɛ4 and HSV1 together increased the risk of AD development [OR 2.71; 95% CI 1.08-6.80]. HSV1 together with the presence of the APOE ɛ4 allele increases the risk of developing AD.