Review Question - QID 214603

A 26-year-old man presents to his primary care physician with a 3-day history of fever, fatigue, and headache. He says that he recently returned from a hiking vacation in the Shenandoah Valley where he passed through parts of Virginia and West Virginia. During the trip, he tried to live off the land and acknowledges that his diet included freshly hunted game and mountain stream water. He started experiencing a fever, myalgias, fatigue, and headaches about 2 days after returning from his trip. His past medical history is significant for migraines though he is not currently taking any medications. He has no drug allergies. On presentation, his temperature is 102.0°F (38.8°C), blood pressure is 115/72 mmHg, pulse is 105/min, and respirations are 17/min. Physical exam is unremarkable. A blood smear is obtained and stained with the results shown in Figure A. Which of the following is the most likely cause of this patient's symptoms?