Caught infection in the end and felt sick (6)
I believe the answer is:
nailed
'caught' is the definition.
(I've seen this before)
'infection in the end and felt sick' is the wordplay.
'in the end' indicates one should take the final letters.
'and' is a charade indicator (letters next to each other).
'felt sick' becomes 'ailed'.
The final letter of 'infection' is 'n'.
'n'+'ailed'='NAILED'
(Other definitions for nailed that I've seen before include "Fixed with pins" , "Fastened with metal pins" , "Caught, collared" , "Properly fixed" , "Attached by means of a pointed piece of metal" .)