- www.cdc.gov -- Centers for Disease Control and Prevention
- www.niaid.nih.gov -- National Institute of Allergy and Infectious Diseases
- www.ninds.nih.gov -- National Institute of Neurological Disorders and Stroke
- www.aan.com -- American Academy of Neurology
Review Date: 05/03/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.