Peripheral blood leukocytes containing ehrlichial morula in patients with human monocytic ehrlichiosis (A) and human granulocytic anaplasmosis (B and C). A and B, a morula (arrow) containing Ehrlichia chaffeensis in a monocyte in patient with HME. B and C; a morula (arrowhead) containing Anaplasma phagocytophilum in a neutrophil in patient with HGA. Wright stains, original magnifications ×1,200. (A From Walker DH, Dumler JS. Ch. 190: Ehrlichia chaffeensis (Human Monocytotropic Ehrlichiosis), Anaplasma phagocytophilum (Human Granulocytotropic Anaplasmosis), and Other Ehrlichiae. In: Mandell, Bennett, & Dolin, editors. Principles and Practice of Infectious Diseases, 6th ed. Church Livingstone; 2005. Permission requested from Elsevier. B From Siberry GK, Dumler JS. Ch. 228: Ehrlichiosis and Anaplasmosis. In: Kliegman, editor. Nelson Textbook of Pediatrics, 18th ed. Saunders; 2007. Permission requested from Elsevier. C From Walker DH, Paddock CD, Dumler JS. Emerging and Re-emerging Tick-Transmitted Rickettsial and Ehrlichial Infections. Medical Clinics of North America, 2008; 92(6). Permission requested from Elsevier.)