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index case Syllabification: in·dex case
(also index patient)

Definition of index case in English:


The first identified case in a group of related cases of a particular communicable or heritable disease.
Example sentences
  • The fifth cluster of infection was the family of the index patient.
  • Four of his family members developed the infection; the brother of the index patient had the earliest date of onset.
  • We found no studies comparing index patients given chemoprophylaxis with those who were not.

Definition of index case in:

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