For a number of years I've had several potted impatiens plants of different strains. Many have been propagated via cuttings from the same original plant. This year, many of the plants all appear to have caught either a virus or bacterial infection. I don't believe this is necrotic spot virus, as there are not many discernible dead spots on the leaves, although there are a couple.
Many of the leaves towards the tops of the growing tips appear to have a 'bubbled' appearance, and are shriveling up - looking curled and distorted. The growing tips themselves are very curled and brown. No flowers or buds are forming. This is affecting only two of the three species I have. The other one seems to have escaped infection, which leads me to believe it might be a host specific virus.
I've attached a picture. Does anyone have any idea what this is? Can it be cured or should I destroy all the infected plants, get rid of the soil and start again?