Isolation and Determination of Antibacterial Sensitivity Characteristics of Staphylococcus aureus from Lactating Cows in West Shewa Zone, Ethiopia

Table 3

Binomial logistic regression analysis of association between bovine mastitis and risk factors.

Characteristics	Category	Mastitis positive (%)	Univariate		Multivariate
			OR (95% CI)	value	OR (95% CI)	value
Districts	Wolmera	28 (34.57)	1.0
	Ambo	33 (42.86)	1.42 (0.75–2.71)	0.285
	Toke kutaye	19 (37.25)	1.12 (0.54–2.33)	0.754
	Bako tibe	17 (34.69)	1.01 (0.47–2.11)	0.988
Agroecology	Highland	28 (34.57)	1.0
	Midland	52 (40.62)	1.30 (0.73–2.32)	0.381
	Lowland	17 (34.69)	1.01 (0.47–2.11)	0.988
Breeds	Local	42 (36.52)	1.0
	Cross	55 (38.46)	1.09 (0.65–1.81)	0.749
Farm types	Intensive	4 (14.81)	1.0		1.0
	Semiintensive	18 (36.73)	3.34 (1.07–12.75)	0.051	2.45 (0.31–22.64)	0.40672
	Extensive	75 (41.21)	4.03 (1.48–14.17)	0.013	8.20 (1.33–68.25)	0.03451
Age group of the animal	Adult	43 (35.25)	1.0
	Medium	33 (37.93)	1.12 (0.63–1.99)	0.691
	Young	21 (42.86)	1.38 (0.70–2.71)	0.353
Lactation stage	Early	28 (29.17)	1.0		1.0
	Mid	41 (43.16)	1.84 (1.02–3.38)	0.045	5.03 (1.48–19.27)	0.01275
	Late	28 (41.79)	1.74 (0.91–3.37)	0.096	6.12 (1.55–27.32)	0.01229
Parity level	Moderate	51 (30.54)	1.0		1.0
	Few	43 (50.00)	2.27 (1.33–3.90)	0.003	2.32 (0.78–7.16)	0.13117
	Many	3 (60.00)	3.41 (0.55–26.49)	0.186	0.12 (0.00–2.80)	0.19550
Animal’s body condition	Moderate	57 (32.20)	1.0		1.0
	Good	17 (50.00)	2.11 (1.00–4.45)	0.049	0.64 (0.12–3.20)	0.58828
	Poor	23 (48.94)	2.02 (1.05–3.89)	0.035	1.14 (0.30–4.22)	0.84861
Number of lactating cows in the herd	Small	80 (35.71)	1.0
	Medium	7 (43.75)	1.40 (0.48–3.90)	0.520
	Large	10 (55.56)	2.25 (0.85–6.11)	0.101
Hand washing before milking	Yes	18 (11.69)	1.0		1.0
	No	79 (75.96)	23.88 (12.6–47.8)	0.000	15.98 (5.6–51.5)	0.0000
Udder washing before milking	Yes	14 (8.86)	1.0		1.0
	No	83 (83.00)	50.22 (24.4–111.3)	0.000	36.90 (12.2–135.6)	0.0000
Current tick infestation of the teat	No	55 (26.44)	1.0		1.0
	Yes	42 (84.00)	14.60 (6.77–35.34)	0.000	34.24 (5.9–253.3)	0.00020
S. aureus	Negative	63 (29.30)	1.0		1.0
	Positive	34 (79.1)	9.11 (4.29–21.24)	0.000	1.15 (0.22–6.09)	0.86272

OR = odds ratio and 1.0 = reference group.