Your husband is in the military, currently stationed in Hawaii. He is training troops in the jungle and recently came into contact with a rats' nest that was contaminated with rat feces. He developed symptoms of sudden high fever, chills, headaches, and vomiting. After the doctor performed a macroscopic slide agglutination test, your doctor reveals that this is a disease called what?

a) Leptospirosis
b) Hantavirus
c) Rat-bite fever
d) Lassa fever