Viruses, but not bacteria, tied to mental decline

Past infection by multiple common viruses may contribute to dementia in some elderly people. Viruses can trigger inflammation in tissues they infect, and inflammation of brain tissue had previously been linked to mental decline.

To explore this connection, Timo Strandberg and his colleagues at the University of Helsinki tested for antibodies to three viruses and two bacteria in 383 volunteers over age 75 who had cardiovascular disease.