Studies have found new evidence of a possible link of Alzheimer's and herpesvirus

Such studies have found that A-beta plaque buildup to be the brain's way of pretecting itself from such viruses

Scientist Joel Dudley and his colleagues were searching through datasets for Alzheimer's disease vulnerabilities to exploit in creating a treatment when they came across a surprising correlation. Many of the brains they looked at had signs of herpesvirus infection. But those from people with Alzheimer's disease had much higher levels of viral DNA than those from healthy people.

We had no intention of looking at viruses, says Dudley, a biomedical informatics researcher at the Icahn School of Medicine at Mount Sinai in New York City, who gives a talk jokingly titled, I went looking for drugs and all I found were these stupid viruses.

There was no evidence whether the herpesviruses contribute to the development of Alzheimer's, or if Alzheimer's patients are just more susceptible to these viruses, which can remain latent in the body long after exposure. Genetic factors also influence a person's risk of developing Alzheimer's. The researchers did find that the viruses interacted with genes linked with Alzheimer's disease, though the implications are still murky.

Dudley has now found himself in the middle of a debate between researchers who believe there is a link between infectious pathogens and the degenerative brain disease, and those who do not. One reason for the controversy, says James Leverenz, a neurologist at the Cleveland Clinic, is that herpesviruses are so ubiquitous, and so many people carry them. The idea that such a common virus could contribute to a devastating disease seemed unlikely to many researchers for decades.