Box blight?

I have a dead patch in my hedge, about 30 cm square, so not too bad compared to my neighbours. Across the road from me, opposite and their neighbour, the hedges are half dead around the two front lawns which have hedges, with brown patches all over covering half to two thirds of the hedges. In the five years of owning my house I have never seen this on my hedge or nearby hedges. The affected bit of my hedge is on the roadside, so the closest part to those other hedges.
So I suspect whatever has affected my neighbours hedges has affected mine also. I am concerned this might spread further, what can I do to prevent this?

 

Hello Cassie23, have a close look at the leaves. If there are caterpillars or webbing, you need to get some treatment on the whole hedge, quickly. I don't know the brand names there, but it will be sachets of a powder containing Bacillus thuringiensis. You dilute the powder in water and the bacteria target only caterpillars, so harmless to other organisms. Preventative and cure. If it is Box moth, you could perhaps tip off your neighbours, to prevent re-infestation?

 

I have a small hedge about 4 yards long and two trimmed bushes both in Pots. one Spherical and the other cone shaped, This plant is in a large Ali Baber pot about 3 ft tall. This die back was visible in spring but now they are dead. There is no sign of new growth or any visible pests like caterpillars.
I assume this is a specific disease peculiar to box. I live in Welwyn Garden City, Hertfordshire where Box hedges are not common so I do not know how common it might be locally

 

I've spotted the caterpillars for the first time this year, they have caused chaos but there is new growth coming back.
I'm guessing the caterpillars are pretty much finished by now, I could only find a couple.