Morulae of anaplasmosis in circulating neutrophils

A 51-year-old man with no significant past medical history presented with a 5-day history of fever, malaise, and diffuse myalgias with no recollection of a tick bite. He was found to have thrombocytopenia, elevated transaminase levels, and renal insufficiency. Examination of the peripheral smear suggested the diagnosis of anaplasmosis. He was started on a course of doxycycline, with eventual complete resolution of symptoms. The peripheral smear (1000x, "feather edge") shows morulae of anaplasmosis in the patient's granulocytes. Photomicrographs B and C were taken from the extreme feather edge and show exploded neutrophils containing well-delineated morulae.