From an article cited in the OP:

"Neurosurgeons were more likely to die of Alzheimer disease, other nonneoplastic nonvascular nervous system disease, leukemia, and aircraft accidents, when compared with the general population."

That looks like persons exposed to the brains of patients may be catching something.

What if it was a germ? How would one go about finding it? Where would one find the non-infected population with which to compare? It may be a combination of a germ and genetics and that germ may be pervasive in our environment, but that doesn't mean the germ cannot be isolated or even eradicated. So it is worth investigation. We may need to find people (monks?) who have lived without exposure to people with dementia, an interesting anthropological problem imho.

There are some viruses that basically everyone gets that then lay latent for the rest of your life. So yes if one of those were a cause then epidemiological data wouldn't be much help.

Not a crazy thoery, one of the complications of measles is a fatal encephalitis that occurs 5-20 years later.

Be nice if they figured it out, Alzheimer's Disease means years of suck quality of life for everyone.

Worst case: they are getting it, but not finding out until they themselves reach old age.

I think even that would be noticed by now. If almost every person that worked in a nursing home 30 years ago are getting Alzheimer's.

But why assume that people who work in nursing homes will be more exposed? Work is only part of the day. A great many more people live with elderly/dementia patients in their homes. We are all in contact with such people daily. If there were a germ that we could 'catch', I wouldn't assume that people in nursing homes were a special population. We may all have it.