my main concern would be going back in to your own lofts , wear differant clothes alltogether, and a good wash [dont mean that in a bad way ] differant shoes,
as far as the lads birds go, i can see your worried , its very difficult on line , without seeing the birds , but virkon s in water would at least help stop things get worse, even milton , which contains bleach, [very little] would help, but would it not be possible to ask any of your local good fanciers for their advice, it would probably be wise to take the worst to the vet ,,but that would cost,,,but would maybe worth it in the end,, hope you get things sorted westy , try not to worry its not your fault ,,just be very carefull with your own