1. Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, Maryland
2. Enteric Diseases Epidemiology Branch, Division of Foodborne, Bacterial, and Mycotic Diseases, National Center for Zoonotic, Vectorborne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta Georgia
3. Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland