Listeria Species Occurrence and Associated Risk Factors and Antibiogram of Listeria Monocytogenes in Milk and Milk Products in Ambo, Holeta, and Bako Towns, Oromia Regional State, Ethiopia

Table 3

Results of logistic regression analysis of farm-level potential risk factors for isolation of Listeria species.

Risk factors	Categories	Number tested	Number of positive sample (%)	Univariable		Multivariable
				Or (95% CI)	value	Or (95% CI)	value
Town	Bako	16	3 (18.75)	1.0	—
	Ambo	21	7 (33.33)	2.17 (0.46–10.20)	0.328
	Holeta	11	7 (63.64)	7.58 (1.31–43.92)	0.024
Farm hygiene	Poor	23	6 (26.09)	1.0		1.0	—
	Good	13	5 (38.46)	1.77 (0.41–7.58)	0.441	1.69 (0.27–10.46)	0.570
	Moderate	12	6 (50.0)	2.83 (0.65–12.26)	0.164	3.53 (0.51–24.59)	0.203
Level of education of workers	College and above	14	4 (28.27)	1.0
	Secondary	13	4 (30.77)	1.11 (0.21–5.80)	0.901
	Elementary	15	5 (33.33)	1.25 (0.26–6.07)	0.782
	Illiterate	6	4 (66.67)	5.0 (0.64–39.06)	0.125
Herd size	Smallholder (≤10)	24	3 (12.50)	1.0	—
	Medium (10–50)	17	8 (47.06)	6.22 (1.33–29.01)	0.020
	Large (≥50)	7	6 (85.71)	42 (3.67–481.03)	0.003
Farm size	Small	24	3 (12.50)	1.0	—
	Large	24	14 (58.33)	9.8 (2.28–42.06)	0.002
Number of lactating cows	≤5	21	2 (9.52)	1.0	—
	6–13	18	8 (44.44)	7.6 (1.35–42.80)	0.021
	≥14	9	7 (77.78)	33.25 (3.90–283.45)	0.001
Management system	Extensive	12	1 (8.33)	1.0		1.0	—
	Semi-intensive	14	5 (35.71)	6.11 (0.60–62.23)	0.126	2.93 (0.18–48.45)	0.452
	Intensive	22	11 (50.00)	11 (1.21–100.39)	0.034	6.38 (0.54–75.95)	0.143
Training on food safety	Yes	23	8 (34.78)	1.0
	No	25	9 (36.00)	1.05 (0.32–3.45)	0.930
Washing cows udder before milking	No	7	2 (28.58)	1.0	—
	Yes	41	15 (36.59)	1.44 (0.25–8.37)	0.683
Materials used for udder drying	Collective towel	13	2 (15.38)	1.0	—	1.0	—
	Without towel/just with hand	10	4 (40.00)	3.67 (0.51–26.22)	0.196	3.72 (0.26–53.45)	0.333
	Individual towel	25	11 (44.00)	4.32 (0.79–23.68)	0.092	2.52 (0.31–20.52)	0.388
Source of water for udder and utensil washing	River	12	2 (16.67)	1.0	—	1.0	—
	Pipe	36	15 (41.67)	3.57 (0.68–18.72)	0.132	1.53 (0.21–11.11)	0.672
Washing hands before milking	Yes	30	10 (33.33)	1.0	—
	No	18	7 (38.89)	1.27 (0.38–4.29)	0.697
Time of udder washing	Before milking	25	7 (28.00)	1.0	—	1.0	—
	No washing	6	2 (33.33)	1.29 (0.19–8.67)	0.796	1.54 (0.16–14.73)	0.710
	Before and after milking	17	8 (47.06)	2.29 (0.63–8.32)	0.210	2.29 (0.46–11.53)	0.314