Tolerating nothing that may start epidemic (7,4)

I believe the answer is:

patient zero

'that may start epidemic' is the definition.
(earliest known carrier of a disease)

'tolerating nothing' is the wordplay.
'tolerating' becomes 'patient' (patient can mean showing tolerance).
'nothing' becomes 'zero' (synonyms).
'patient'+'zero'='PATIENT ZERO'

I've seen this clue in The Guardian.

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