This information is from David A. Dick, Agricultural Weed Specialist, West Virginia Department of Agriculture
Here’s what we know (that I’m aware of):
1) It occurs in at least 3 counties in WV
2) It has also been found in Indiana
3) There are areas where it has killed 100% of the stiltgrass present
4) According to our plant pathologists, it looks like a fairly common fungal blight, although we are still trying to get a positive ID
5) Similar symptoms are showing up on Jewelweed, deer tongue grass, and some sedges (not sure if it is the same pathogen)
6) Likely spread as widely as it has due to a very wet spring, when most diseases get spread among plants.
That’s what we have so far. The exciting part is that it is impacting stiltgrass. However, it is probably not selective and has likely become abundant this year due to our spring weather patterns.
An online article with images (some included below):