A 56-year-old man presents to the hospital with two weeks of fever, fatigue, headache
, and myalgia. The patient spent the last three months hiking in Africa, North America, and South America. Bloodwork reveals elevated hepatic transaminases as well as severe anemia. A thick and thin smear of peripheral blood is prepared with Giemsa stain. Examination of the smears under light microscopy
shows cross-shaped inclusions within several erythrocytes. Which of the following organisms is most likely responsible for this patient’s findings?