Ursula, there are so many viruses around, many of these have hundreds if not thousands of possible hosts, others are more specific in their choice. I didn't remove these plants to protect lilies specifically, rather I don't want all of my tulips or other plants to be destroyed.
Generally speaking I believe most plants are - or will soon be - infected with at least one virus. Most of them can handle this, but problem arises when they get infected with several.
Ponder the following situation, you grow some plants that are infected with one virus, then you buy other plants and these happen to be infected with yet another virus. As long as they only had one, they showed no symptoms. However arriving at their new home they soon start to show symptoms as they now are infected with two viruses and this becomes too much for the plants. In this situation one perhaps blames the grower, but that may not always be completely fair.
Sorry if you thought this was discouraging, but all plants have their problem and from what I seen most hybrid lilies are rather though as I so far had far less troubles with viruses on lilies, than on other plants
. At any rate a hybrid that is very susceptible to virus, will soon disappear from commerce.
I suspect the biggest danger for peonies is that they are rather long lived, and the longer you have a plant, the more likely it is to pick up different viruses.They are however usually not troubled by insect vectors, so the biggest risk of virus transferral might be the gardener.
Don't worry about this too much as it's not worth it, you may never have a problem rather just continue to enjoy your plants. There are lily hybridizers that always keep a few virused lilies around, just to make sure that their new creations has some basic resistance.
