Wow, I never would have thought of chicken poop. While I definitely know the connection between that and illness (that must have been awful, Emily), I am so not a germaphobe. I went through a phase where I tried to use hand sanitizer a lot (around the time of the bad flu, in 2009-10), I eventually stopped, after reading a lot of articles saying it does more harm than good, especially for kids.
I do ride in farm country, but I suspect not the large chicken farms you experienced in VA. So, I keep digging my hands in dirt and touching things, using soap and water when I can.