If that is fully developed and not just a hope this test works, that is good news. I hope very much that ours are resistant as some of them may have originated 1000 years ago, so their loss would be a cultural and historic as well as an ecological loss.
Slim, the Forestry Commission here are really worried about the Emerald Ash borer, and they are on the look out. That, sadly is all that can be done. Because of chelara, there are restrictions on ash imports, so hope that will be enough.
The best thing you can do for ash trees is to make sure any tree surgery carried out on them is with clean equipment, and try to ensure that there is plenty of air around them. The fungus of chelara is not that long lived, so if they have plenty of air, it is less likely to be able to settle and survive.