Alzheimer’s, Parkinson’s, and dementia have existed for thousands of years. Ancient Greek and Roman physicians associated old age with increasing dementia. Egyptian and Ayurveda writings, the Bible, and Galen’s writings described symptoms resembling Parkinson’s. In 1817, Dr. James Parkinson described the symptoms of shaking associated with Parkinson’s. In 1901, Dr. Alois Alzheimer described the mental decline and memory loss of Alzheimer’s, and suggested microorganisms may cause senile plaque. In 1912, Dr. Frederic Lewy described microscopic particles, in the brains of Parkinson’s patients, now named Lewy bodies.

Dr. Parkinson, Dr. Alzheimer, and Dr. Lewy did not have the tools to diagnose immortal infection, explain the origin of abnormal proteins, or identify infectious causes of mental decline. When a chronic disease persists in the population for 1000’s of years, even a small genetic cost per generation would eliminate the disease from the population, which makes genetic causes unlikely. Any disease described and named after a doctor, before modern diagnostic tools were available, should be reexamined for infectious causes.