Not in Bolton but I’m from there, so these are my takes albeit from a distance.
Speaking to my mum, the areas with highest rates of infection include those areas that also have high populations of south Asian people. One place in particular is made up of mainly 2/3 bed terraced houses with no front or back garden, maybe a back yard. These tend to be inter generation houses. The community there is also very close knit and if you don’t live with your family, then you’re only a few doors down from them. They spend a lot of time socialising. These community members tend to be either self employed or work in customer facing roles - taxi drivers, warehouse, hospitality, retail.
You also have high spikes in areas of lower income. Again in these areas you are getting people doing jobs that can’t be done at home and are customer facing. These areas tend to be very tight knit too, with people spending a lot of time with friends.
Both these areas, then send their kids to school or pass it to customers in other areas and infection rates creep up.
From my FB, there are some people in my hometown who believe it’s a hoax. I also know vulnerable people who aren’t taking any precautions and we’re still sending their kids to school because it’s easier.
It’s like a perfect storm. The correct amount of people who believe it’s a hoax, high numbers of BAME, all tightly packed together.