Received: 12 October 2017
Accepted: 20 February 2018
First Online: 2 March 2018
Ethics approval and consent to participate
: Ethics approval and participant consent was not necessary as samples were collected for purposes of nonresearch disease surveillance and were deidentified prior to transmission and analysis at CDC. The GISP protocol has been reviewed periodically by the CDC Human Research Protection Office and deemed to be a surveillance and disease control activity and not to be human subject research.
: Not applicable
: The authors declare that they have no competing interests.
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