Q.How can I treat a ‘virus’ on my hosta leaves?
Some of my hosta leaves are turning tan to yellow in blotchy patches. I have cut those off and bagged them. What can I do to treat this?

Here is an extension article that discusses spots on hosta leaves.
http://www.extension.umn.edu/garden/diagnose/plant/annualperennial/hosta/leavesspots.html
Based on your description, it sounds like maybe you have sunscald? If so, then this article will help you:
https://www.gardeningknowhow.com/plant-problems/environmental/leaf-scald-in-plants.htm
Happy gardening!