TABLE 2.

Number and Percentage of Outbreaks With Reported Mode of Transmission by Outbreak Setting of School or Childcare Facility, Reported Through the National Outbreak Reporting System, 2009–2019

Mode of Transmission	School (%) N = 2623	Childcare (%) N = 1972	Both School and Childcare (%) N = 38	Total (%) N = 4633
Person-to-person	2209 (84.2)	1733 (87.9)	29 (76.3)	3971 (85.7)
Unknown	296 (11.3)	202 (10.2)	6 (15.8)	504 (10.9)
Food	98 (3.7)	22 (1.1)	3 (7.9)	123 (2.7)
Environmental	7 (0.3)	7 (0.4)	0	14 (0.3)
Animal contact	6 (0.2)	5 (0.3)	0	11 (0.2)
Water	7 (0.3)	3 (0.2)	0	10 (0.2)