Quote from Paul Zimmerman:

"It is increasing in frequency, including in my own garden. I have about four plants that will be dug up because they are infected. We will talk more about how to deal with it later and also why it's not a reason to stop growing roses. However, in this post I want to address a rumor that says the cause of RRD are The Knock Out Rosesî."

Here is a link that might be useful: link for above