1. Centers for Disease Control and Prevention , Division of Vector-Borne Diseases, Fort Collins, Colorado , USA
2. Wyoming Department of Public Health , Cheyenne, Wyoming , USA
3. Arkos Health , Bismarck, North Dakota , USA
4. North Dakota Department of Health and Human Services , Bismarck, North Dakota , USA
5. Oklahoma State Department of Health , Oklahoma City, Oklahoma , USA
6. Minnesota Department of Health , St Paul, Minnesota , USA
7. Centers for Disease Control and Prevention , Division of Foodborne, Waterborne, and Environmental Diseases, Atlanta, Georgia , USA