NoroSTAT Data Table

The following table shows the data for suspected and confirmed norovirus outbreaks reported by state health departments in Massachusetts, Michigan, Minnesota, Nebraska, New Mexico, Ohio, Oregon, South Carolina, Tennessee, Virginia, Wisconsin, and Wyoming to CDC through the National Outbreak Reporting System (NORS) by week of illness onset, 2012-2020*†‡§.

Norovirus Outbreaks Reported by State Health Departments by Week of Illness Onset, 2012-2019

 

Norovirus Outbreaks Reported by State Health Departments by Week of Illness Onset, 2012-2019
Week Minimum,
2012-2018
Maximum,
2012-2018
2018-2019 2019-2020
1-Aug 1 6 8 5
8-Aug 3 14 4 4
15-Aug 4 10 5 2
22-Aug 4 8 7 6
29-Aug 2 4 7 11
5-Sep 2 9 4 9
12-Sep 5 10 11 12
19-Sep 4 9 8 11
26-Sep 3 16 6 12
3-Oct 2 14 5 6
10-Oct 4 14 13 13
17-Oct 5 15 10 12
24-Oct 5 15 11 11
31-Oct 12 21 13 25
7-Nov 5 28 12 24
14-Nov 12 26 21 25
21-Nov 10 32 40 18
28-Nov 24 58 54 44
5-Dec 33 52 62 35
12-Dec 33 76 79
19-Dec 19 50 36
26-Dec 15 59 67
2-Jan 35 76 81
9-Jan 37 64 65
16-Jan 44 76 56
23-Jan 42 79 61
30-Jan 47 63 48
6-Feb 35 64 53
13-Feb 35 64 50
20-Feb 25 70 49
27-Feb 28 95 68
6-Mar 32 77 53
13-Mar 35 70 49
20-Mar 22 58 51
27-Mar 32 76 47
3-Apr 25 49 53
10-Apr 20 32 32
17-Apr 22 37 21
24-Apr 16 29 18
1-May 9 26 22
8-May 9 26 27
15-May 9 31 10
22-May 6 16 16
29-May 7 13 11
5-Jun 4 14 8
12-Jun 5 11 8
19-Jun 6 13 3
26-Jun 4 7 3
3-Jul 3 9 9
10-Jul 4 17 7
17-Jul 6 11 6
24-Jul 4 14 3

*Michigan and South Carolina joined the NoroSTAT network at the start of the 2015-16 seasonal year; 2012-15 data from these states have been added for comparison.

†Massachusetts and Virginia joined the NoroSTAT network at the start of the 2016-17 seasonal year; 2012-16 data from these states have been added for comparison.

‡New Mexico and Wyoming joined the NoroSTAT network at the start of the 2018-19 seasonal year; 2012-2018 data from these states have been added for comparison.

§Nebraska joined the NoroSTAT network at the start of the 2019-20 seasonal year; 2012-2019 data from this state have been added for comparison.

Page last reviewed: December 18, 2019