M8, with all due respect, you dont seem to have learned from this. You posted that you had introduced a fish without quarentine and were told how irresponsible this was. You claimed over and again that you new the supplier very well and that it had been quarentined for a long period. Once the ineviitable happened, as you had been warned, you insisted it was an air problem and only over several days did you slowly release bits of information. Now you tell us that you intriduced an Israeli Koi 2 weeks before it happened, again information you failed to tell us before when we were trying to help you.
Once again you have asked for help and are ignoring it. Even if it isn't KHV there are a hundred and one other things that could still be in your pond, your fish, your filters etc, you are heading for another costly, cruel disaster if you dont head peoples advice here.
Kill the fish, burn them, dissinfect EVERYTHING until you cant dissinfect any more, them dissinfect again, twice. Then start afresh with a few small fish from a different supplier completely to the ones you've used before. This is the only way you can be sure you get it all and it wont happen again.
This may sound harsh but I tell it like I see it.