Chronic Bacterial and Viral Infections in Neurodegenerative and Neurobehavioral Diseases

Nicolson, Garth L.

Often, patients with neurodegenerative or neurobehavioral diseases have chronic, neuropathic infections that could be important in disease inception, disease progression, or increasing the types or severities of signs and symptoms. Although controversial, the majority of patients with various neurodegenerative or neurobehavioral conditions, such as amyotrophic lateral sclerosis, multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, and autistic spectrum disorders, show evidence of central nervous system or systemic bacterial and viral infections. For example, using serology or polymerase chain reaction evidence of Chlamydia pneumoniae, Borrelia burgdorferi, Mycoplasma species, human herpesvirus-1 and -6, and other bacterial and viral infections revealed high infection rates that were not found in control subjects. Although chronic infections were not found in some studies, and the specific role of chronic infections in neurological disease pathogenesis has not been determined or is inconclusive, the data suggest that chronic bacterial or viral infections could be common features of progressive neurodegenerative and neurobehavioral diseases.