1. Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
2. Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México City, México
3. Division of Immunoparasitology, Tropical Medicine Institute, Universidad Central de Venezuela, Caracas, Venezuela, and Experimental Institute Jose Witremundo Torrealba, Universidad de Los Andes, Trujillo, Venezuela
4. Hospital Infantil de México, Federico Gómez, México City, México
5. Division of Cardiology, Anis Rassi Hospital, Goiânia, Brazil