Wipe out cholera selecting hosts (5)
I believe the answer is:
erase
'wipe' is the definition.
(I've seen this in another clue)
'cholera selecting hosts' is the wordplay.
'hosts' says the answer is hidden in the clue.
'ERASE' is hidden within 'cholera selecting'.
'out' acts as a link.
(Other definitions for erase that I've seen before include "To remove all trace" , "Clear" , "Blot out" , "score" , "Obliterate" .)