Characterized by a sudden onset of shortness of breath with rapidly evolving pulmonary edema, Hantavirus can prove fatal, despite mechanical ventilation and intervention with potent diuretics.

Deer mice are also primary carriers of Lyme disease, caused by the bacterium Borrelia burgdorferi, transmitted to humans through the bite of infected ticks. Symptoms include fever, headache, fatigue and a skin rash. If left untreated, Lyme disease can spread to joints, the heart and the central nervous system.