Affected by ruse employed by nurse (8)
I believe the answer is:
stricken
'affected' is the definition.
('stricken' can be similar in meaning to 'affected')
'ruse employed by nurse' is the wordplay.
'ruse' becomes 'trick' (I've seen this before).
'employed by' is an insertion indicator.
'nurse' becomes 'sen' (I've seen this before).
'trick' inserted within 'sen' is 'STRICKEN'.
'by' acts as a link.
(Other definitions for stricken that I've seen before include "Wounded" , "Hit" , "Seriously affected (by, eg, condition)" , "Laid low (by illness)" , "Suffering from illness" .)