Lettuce plants... systemic virus?

yah we have it to where it will just affect some branchs sometimes… like maybe they were next to a dud that we pulled and caught it on contact. Today at work tmv was no new surprise and they said they suspected it but had testing done and it came back negative. there cure is eradication and they do have a good eye for it early in veg. im starting to get the eye for it. Its not that hard to find when its next to a healthy plant