1. Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
2. Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
3. Division of Infectious Diseases, New York Medical College, Valhalla, New York, USA
4. The Lyme Disease Research Center, Division of Rheumatology, Department of Medicine, Johns Hopkins University School of Medicine, Lutherville, Maryland, USA