Table 2. Number and age of laboratory-confirmed COVID-19 cases, connection to outbreaks in other settings, by week of illness onset of the first case in a school outbreak^a, Germany, 28 January–31 August 2020 (n = 216).

Outbreakb number	Week of illness onseta	Number of cases reported	Age		Other setting linked to school outbreak
			< 21: in years (n)	n ≥ 21
1	9	2	13 (1)	1	None
2	9	2	0	2	None
3	10	5	15 (1), 16 (1), 17 (1)	2	None
4	10	2	19 (2)	0	None
5	10	25	13 (13), 14 (7)	5	None
6	11	5	0	5	None
7	11	4	0	4	None
8	11c	11	20 (1)	10	None
9	11	3	13 (1), 14 (1)	1	None
10	11	2	0	2	None
11	11	5	17 (1)	4	None
12d	12	3	12 (2)	1	None
13d	12	8	8 (1), 10 (1), 12 (1)	5	None
School closure 16–18 March to 20 April 2020 (calendar weeks 12 to 17)
14	20	4	7 (2), 8 (1), 10 (1)	0	None
15	20	4	8 (2), 10 (1)	1	None
16	21	3	10 (3)	0	Household
17	22	5	17 (1)	4	None
18	22	2	15 (1), 16 (1)	0	None
19	22	3	10 (1), 12 (1)	1	None
20	23	3	8 (1), 13 (1)	1	Household, accommodation, kindergarten, workplace
21	23	4	14 (1), 15 (1)	2	None
22	23	8	6 (1), 11 (1), 12 (1), 13 (2)	3	None
23	24	2	17 (1), 18 (1)	0	None
24	25	2	12 (1), 13 (1)	0	Household, household, householde
25	25	2	0	2	None
26	25c	9	17 (1), 18 (1), 20 (2)	5	None
27	25	7	6 (1), 10 (1), 17 (1)	4	None
28	27	2	10 (1), 11 (1)	0	Household, household, household
29	27	6	10 (4)	2	None
30	28	5	15 (1), 17 (1), 18 (1)	2	None
31	28	2	0	2	None
32	28	5	7 (1), 8 (1)	3	None
33	28	3	6 (1), 7 (1)	1	None
34	28c	7	16 (2), 17 (1), 18 (1), 19 (1)	2	None
35	29	4	0	4	None
36	30	2	0	2	None
37	30	3	11 (1), 15 (1)	1	None
38	31	5	0	5	None
39	33	2	17 (1), 18 (1)	0	None
40	33	2	10 (2)	0	None
41	33	5	15 (4)	1	None
42	33	2	0	2	None
43	34	9	12 (1), 13 (3), 17 (3), 19 (1)	1	Householdf
44	34	8	12 (1), 13 (1)	6	None
45	34	2	7 (1), 8 (1)	0	None
46	34	2	11 (2)	0	None
47	35	3	17 (1)	2	None
48	35	2	19 (1)	1	None

COVID-19: coronavirus disease.

^a Alternatively by week of reporting (n = 7).

^b An outbreak was defined as at least two cases reported by a local public health authority for the same school.

^c Vocational school where students might attend teaching only on 2 days per week.

^d The reported day of illness onset of the first case was 16 March 2020 in both outbreaks.

^e Further events are associated with this outbreak.

^f This household outbreak had only one case. Reasons for an outbreak with one case could be contact tracing management or that secondary cases were attributed to another outbreak.

Data source: mandatory notifications of laboratory-confirmed COVID-19 infections from the national surveillance system.