Earlier this year, researchers reported details of 2 curious medical cases that left clinicians stumped. In one, after sustaining numerous tick bites, a Kansas man began experiencing fever, fatigue, anorexia, nausea, and vomiting. Doxycycline, prescribed because some tickborne illnesses respond to this drug, brought no improvement. His condition rapidly deteriorated, and despite hospitalization and additional treatment with antimicrobials, he experienced multiorgan failure and shock, dying about a week later.