ABSTRACT
Anaplasmosis and ehrlichiosis are similar in that both diseases are caused by Gramnegative rickettsial bacteria, infect blood cells or blood platelets, and are transmitted by ticks. Anaplasmosis, which is also called human granulocytic anaplasmosis, is produced by Anaplasma phagocytophilum. This pathogen infects blood neutrophils; these blood cells are 10-12 µm in diameter and have a multilobed nucleus (Figure 18.1). Neutrophils function in phagocytosis and engulf bacteria and fungi inside the body; their deaths in great numbers form pus.
