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Start and end dates for outbreak periods as defined in the Appendix. The total number of weekly cases during the period is shown, along with the total change in the cumulative case count as reported by the CDC.
| Outbreak period | Start | End | Total Weekly Cases |
|---|---|---|---|
| 1 | February 20, 2011 | October 15, 2011 | 82 |
| 2 | March 31, 2013 | July 6, 2013 | 21 |
| 3 | January 26, 2014 | September 13, 2014 | 401 |
| 4 | November 30, 2014 | May 30, 2015 | 46 |
| 5 | April 17, 2016 | June 11, 2016 | 18 |
