Case Study 7 A 60-year-old male from Boise, Idaho, had a 1-month history of intermittent fevers and headaches. He reported a fever of 105º F with a headache for three days. A second fever presented 13 days later that lasted two days. He finally sought medical attention when he had his third fever 26 days after the first symptoms. His history was remarkable for having camped in a cabin in the

A 60-year-old male from Boise, Idaho, had a 1-month history of intermittent fevers and headaches. He reported a fever of 105º F with a headache for three days. A second fever presented 13 days later that lasted two days. He finally sought medical attention when he had his third fever 26 days after the first symptoms. His history was remarkable for having camped in a cabin in the Bear Valley region of Idaho.

Laboratory values were:

The diagnosis was made on the Giemsa-stained blood smear shown in the image. What is the most likely diagnosis of this man?