1. Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia;
2. Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia;
3. UnityPoint Medical Primary Care, Johnston, Iowa;
4. UnityPoint Health, Cedar Rapids, Iowa;
5. State Hygienic Laboratory at the University of Iowa, Coralville, Iowa