A germ theory for Alzheimers?

Gee:  I don't recall reading some of the reasons given in this NPR article as to why there are some grounds for suspecting that Alzheimer's Disease is caused by an infection:

Norins is quick to cite sources and studies supporting his claim, among them a 2010 study published in the Journal of Neurosurgery showing that neurosurgeons die from Alzheimer's at a seven-fold higher rate than they do from other disorders.

Another study from that same year, published in The Journal of the American Geriatric Society found that people whose spouses have dementia are at a six-times greater risk for the condition themselves.

Contagion does come to mind. And Norins isn't alone in his thinking.

In 2016, 32 researchers from universities around the world signed an editorial in the Journal of Alzheimer's Disease calling for "further research on the role of infectious agents in [Alzheimer's] causation." Based on much of the same evidence Norins encountered, the authors concluded that clinical trials with antimicrobial drugs in Alzheimer's are now justified.