Table 2. Influencing factors on the outbreak size of bacillary dysentery in China, 2008–2024.

Variable	Outbreaks, n (%)	Univariate			Mutivariate
		OR (95% CI)	P		aOR (95% CI)	P
Note: - indicates that the variable was not included in the multivariable model. Abbreviation: aOR=adjusted odds ratios; CI=confidence interval.
Year
2008–2013	113 (64.2)	1			1
2014–2019	56 (31.8)	0.2 (0.02, 1.8)	0.16		0.2 (0.01, 1.7)	0.12
2020–2024	7 (4.0)	0.2 (0.02, 1.2)	0.08		0.2 (0.01, 1.4)	0.10
Area
Urban	43 (24.4)	1			−	−
Rural	133 (75.6)	1.4 (0.7, 2.8)	0.34		−	−
Setting
Other	8 (4.5)	1			1
Kindergarden	18 (10.2)	4.5 (0.5, 44.4)	0.20		2.1 (0.1, 37.1)	0.61
Primary school	63 (35.8)	14.0 (1.6, 121.4)	0.02		8.3 (0.6, 122.1)	0.13
Middle/High school	42 (23.9)	8.5 (1.0, 75.2)	0.06		4.9 (0.3, 71.0)	0.24
Technical school/College	12 (6.8)	7.0 (0.7, 75.7)	0.11		7.8 (0.4, 150.4)	0.18
Village	33 (18.8)	3.0 (0.3, 28.1)	0.33		2.9 (0.2, 45.4)	0.44
Route of transmission
Unknown	40 (22.7)	1			1
Water-borne	84 (47.7)	5.0 (2.2, 11.4)	<0.001		5.4 (1.9, 15.3)	0.001
Food-borne	42 (23.9)	2.4 (1.0, 6.0)	0.06		2.6 (0.9, 7.7)	0.09
Contact-borne	10 (5.7)	1.1 (0.3, 5.2)	0.88		1.8 (0.3, 11.4)	0.54
Response time, days
≤3	78 (44.3)	1			1
4–7	56 (31.8)	0.6 (0.3, 1.2)	0.14		0.3 (0.1, 0.8)	0.01
≤8	42 (23.9)	0.4 (0.2, 0.9)	0.02		0.3 (0.1, 1.1)	0.07
Duration, days
≤3	33 (18.8)	1			1
4–7	62 (35.2)	2.1 (0.9, 5.0)	0.09		2.9 (1.0, 8.5)	0.05
≤8	81 (46.0)	1.5 (0.7, 3.4)	0.33		3.8 (1.0, 13.8)	0.04
Pathogen
Unclassified	57 (32.4)	1			1
Shigella sonnei	83 (47.2)	4.2 (2.0, 8.5)	<0.001		4.3 (1.7, 10.9)	0.002
Shigella flexneri	33 (18.8)	1.1 (0.5, 2.8)	0.77		1.5 (0.5, 4.5)	0.44
Shigella boydii/Mixed infection	3 (1.7)	4.0 (0.3, 47.0)	0.27		6.8 (0.3, 138.4)	0.21