Thanks malone and thanks kirky.
I did use Chambers Wizard to find that 7 letter anagram but it did not generate the answer.
I tried anagram solver and got it.
I am still working on 20a and 39a.
39a seems like an anagram but cannot work it out.
I have the three letter word and have penciled in the unclueds.
The disease at 28d is obvious but I cannot parse the clue.