As part of the work I'm doing on processing the Registry of Noteworthy Research in Pathology collection, I've just come across a little bit of material on Howard Taylor Ricketts. This is the man who discovered the bacterium that causes Rocky Mountain Spotted Fever (called rickettsia) and epidemic typhus. We have a copy of a letter he wrote to his wife, which is the first mention of his having seen the micro-organism of typhus, nine days after his arrival in Mexico City. The letter was dated December 20, 1909.
"I kept at the microscope this afternoon because I felt pretty sure that I was finding some micro-organisms in the blood taken from the spots of the patients. I think I am not mistaken. They resemble the spotted fever bacilli somewhat, but stain poorly. I hope within a day or two to feel pretty sure one way or another. They are so hard to recognize that I doubt whether any one else here would see them. But I have so strongly suspected a relationship between spotted fever and typhus that I was looking for that very thing. Don't get excited over it, for it may be some accidental affair. However, I shall push it as rapidly as I can, and as soon as possible shall begin a paper so that there would be little delay in publication..."
Think of the excitement he had to have been holding in check, and hoping he wasn't seeing something that wasn't there.
Within six months he died from typhus, at the age of 39.