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, 2012-2022*†‡§.

Norovirus Outbreaks Reported by State Health Departments by Week of Illness Onset, 2012-2022

 

Norovirus Outbreaks Reported by State Health Departments by Week of Illness Onset, 2012-2021
Week Minimum, 2012-20 Maximum, 2012-20 Range, 2012-20 2020-21 2021-22
1-Aug 1 8 7 0 2
8-Aug 3 14 11 1 2
15-Aug 2 10 8 0 3
22-Aug 4 8 4 2 0
29-Aug 2 11 9 1 4
5-Sep 2 9 7 0 3
12-Sep 5 11 6 1 3
19-Sep 4 11 7 1 5
26-Sep 3 16 13 0 3
3-Oct 2 14 12 1 5
10-Oct 4 14 10 0 8
17-Oct 5 15 10 0 0
24-Oct 5 15 10 0 6
31-Oct 12 23 11 0 7
7-Nov 5 28 23 1 4
14-Nov 12 26 14 0 6
21-Nov 10 40 30 0 5
28-Nov 24 58 34 1 15
5-Dec 33 62 29 1 11
12-Dec 33 79 46 0 27
19-Dec 19 50 31 0 11
26-Dec 15 67 52 1 15
2-Jan 35 81 46 5 16
9-Jan 37 65 28 3 7
16-Jan 44 76 32 4 13
23-Jan 42 79 37 5 31
30-Jan 47 63 16 10 41
6-Feb 35 64 29 10 33
13-Feb 35 64 29 13 58
20-Feb 25 70 45 7 51
27-Feb 28 95 67 10 76
6-Mar 32 77 45 15 47
13-Mar 35 70 35 14 61
20-Mar 13 58 45 21 53
27-Mar 11 76 65 17 41
3-Apr 7 53 46 28 53
10-Apr 2 32 30 26 29
17-Apr 2 37 35 17 29
24-Apr 2 29 27 17 30
1-May 3 26 23 16 22
8-May 0 27 27 16 15
15-May 1 31 30 14 16
22-May 3 16 13 4 7
29-May 0 13 13 11 1
5-Jun 1 14 13 7 1
12-Jun 2 11 9 6 2
19-Jun 1 13 12 10
26-Jun 1 7 6 6
3-Jul 1 9 8 3
10-Jul 1 17 16 9
17-Jul 1 11 10 4
24-Jul 2 14 12 4

*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.