1. Department of Medicine and Health Sciences, University of Sonora, Blvd. Luis D. Colosio SN, col. Centro, C.P. 83000, Hermosillo, Mexico
2. Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, Atlanta, Georgia
3. Ministry of Public Health Sonora, General Directorate for Health Promotion and Disease Prevention, Paseo del Canal y Comonfort, Col. Centro, C.P. 83000, Hermosillo,Mexico