Recommended reading to quickly get up to speed on infectious diseases
Since I didn't get an answer, I'll mention what I did. 

My goal was to understand a particular disease well enough to talk intelligently about it while focusing mostly on the statistics. So learning Epidemiology from the ground up wouldn't have been practical in the 4-5 months I had.

I started with a high level patient-oriented book, C. diff in 30 Minutes. That gave me a general understanding of the disease. Then I began reading academic articles. Not only were these useful for citations in my paper, but it also helped expand my understanding. I would notice common terms that kept popping up. Gram-positive, rod shaped, anaerobic, endospore-forming is intimidating at first, but each of these modifiers can be googled individually to build an understanding.

Finally, it was necessary to know how much I needed to know. I began reading about the hypervirulent strain, ribotype 027 with its binary toxin yadda yadda. None of that was actually important for my paper because that level of detail wasn't in the data. 

So while knowing the general landscape was important, knowing each and every detail, for my purposes, wasn't.