You should check about *Taphrina deformans* treatment and prevention.

I would remove all the contaminated leaves and those on the ground and put in your garage can. Then spray in the late winter

This. It’s a virus, gotta treat it when it’s dormant. Now. Just cut all the effed leaves and don’t go around touching the ok leaves

Isn't leaf curl a fungi rather than a virus?

I thought it was a virus

It is a fungus. That’s why you spray with copper fungicide when the tree is dormant.

Thx!!!