Spread illness again, if recent variant (8)

I believe the answer is:

reinfect

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'spread' is the definition.
Both the definition and answer are verbs in their base form.
Perhaps you can see a link between them that I can't see?

'illness again if recent variant' is the wordplay.
'if recent' anagrams to 'REINFECT'.
However, I'm not sure how the anagram is indicated.

Can you help me to learn more?

(Another definition for reinfect that I've seen is " cause bug to appear again".)

I've seen this clue in The Independent.

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