Epidemic and surgeon's focus turns to a little quinine tablet (6)

I believe the answer is:

plaque

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'tablet' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for plaque that I've seen before include "Trophy" , "Commemorative tablet - unwanted film on teeth" , "filling could be the result" , "Unhygienic stuff that grows on teeth" , "Thin film on teeth" .)

I've seen this clue in The Guardian.

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