Mebbid
Aquarium Advice Addict
Good advice mebbid, ive never had to deal with that or a virus fortunately. Dosen't look exactly like NTD i agree...but, either way, since they are just feeders, and they have a virus, you might consider euthanizing them and stearlizing everything with bleach (including buckets, nets siphons) and start again. If you want some nice wild guppies or endlers try adrian hernendaz at swampriveraquatics.com out of florida, he ships nice healthy wild guppies and N class endlers.
It's a virus yes. But it's one that the fish don't care about if the tank is kept clean. It shouldn't ever become an issue once it's cleared up after this time. If it were a lethal virus or they were suffering I could justify euthanizing them. However these fish will be fine with good care.