Rocky Mountain spotted fever contracted along a Canadian road trip: A case report

Rocky Mountain spotted fever, a potentially fatal tick-borne disease thought to be confined to specific climates and geographic locations, is expanding its reach due to climate change. This is demonstrated by a 73-year-old woman who contracted Rocky Mountain spotted fever outside endemic areas during travel in Canada. Presenting with fevers, arthralgia, weakness, non-bloody diarrhea, conjunctivitis, mild cough, and a rash, this patient was initially started on moxifloxacin (400 mg PO/day) for suspected pneumonia. Treatment was changed to doxycycline (100 mg PO twice daily for 7 days) after dermatology was consulted, and Rocky Mountain spotted fever was thought to be higher on the differential. Rocky Mountain spotted fever was confirmed, and the patient responded well to antibiotics, improving by discharge. The disease's expansion into previously thought nonendemic areas is thought to be linked to milder winters and more extreme dry summers, facilitating pathogen development and tick lineage expansion.