"Are tomatillos subject to Fusarium or Ventricillium Wilt? How would they have contracted it?"

I don't know if they're susceptible. (You might search on google.com with search string such as "tomatillo Fusarium.")

But, if they are, it could easily occur because both Fusarium and Verticillium are in the soil. All you need do is work in the infested soil, then continue in a "clean" area. Your contaminated shoes and tools could move the infested soil.

Well, I haven't really worked him a lot, but I guess it's possible something could have been carried to them. Since the tomatillos are closest to the house, I usually start with them and then go to my tomatoes. I still wonder if there could be an insect vector.