After a recent camping trip a boyscout troop leader presented with a high fever (105of), jaundice, and rose-colored spots to the er. he had been to see a doctor at a clinic previously, about a week and a half ago, who put him on acyclovir. however, he was becoming concerned because he couldn't seem to shake this thing. he would run a high fever for about 3-4 days and then when the fever would break, it would come back and he would have another bout with the symptoms. he felt that the drugs weren't really working and he was missing so much work that his boss was becoming concerned. what is the causative agent of the disease that you suspect this man has contracted?