Investigating hepatitis E virus seroprevalence in patients with Alzheimer's disease

Hepatitis E virus (HEV) exposure has been linked to neurologic manifestations and dementia. This study aims to clarify a possible association between HEV and Alzheimer's disease (AD).

We performed a single-center retrospective case-control study of 453 cognitively impaired adults from southern Germany, comparing anti-HEV IgG seropositivity between patients with AD and those with non-AD cognitive impairment. Associations were evaluated using chi-square testing and multivariable logistic regression, including age-stratified analyses.

Overall HEV IgG seroprevalence was higher in the AD group than in the non-AD group (44.5% vs. 37.7%, p = 0.138), with a significant difference in patients aged 60-69 years (46.5% vs. 35.1%, p = 0.040) but not in those aged 70-79 years (46.7% vs. 50.0%, p = 0.646).

These findings suggest that anti-HEV antibodies are more frequent in younger elderly AD patients compared with cognitively impaired individuals of the same age without AD, raising the hypothesis that prior HEV infection may represent a candidate environmental risk factor for AD.