This very remark undermines your snark. We clearly would not look at 'breathes air" or 'drinks water,' precisely because these are factors that are common in the population between those who do and those who do not develop Alzheimer's. It is, in fact, the very fact that the factors that the grandparent mentioned "don't belong in the brain" that is interesting, and suggestive of models other than, for example, "Alzheimer's is an isolated, simple condition that is relatively unaffected by confounds."
It is these very same correlations that can lead us to the likely rocks to turn over, and that is where the newsworthiness and interest derives. Everybody knows about correlation and causation. It's possibly not causative, for example, but seems to be correlative that people who snark about correlation and causation tend to shoot themselves in the feet with their sarcasm. I sure know where I'll look for a deeper explanation, though!
Herpes is also extremely common in the human population (cold sores, anyone?) so I fail to see how this somehow proves your point.
Yes, HHV-6 is common throughout the population, including in the brain. It's an endogenous retrovirus, so is inherited via DNA, or is easily transmitted from person to person, particularly in childhood.
The issue is severity, not presence.
By the way, the variants of herpes in question are HHV-6/7, which are different to the herpes simplex viruses (HSV1/2) that cause cold sores and skin breakouts.
Is not some magical incantation
With just a word or two of proof
We all get closer to the truth
- mfringel the rhetorical safety officer