A case control study of environmental and occupational exposures associated with methicillin resistant Staphylococcus aureus nasal carriage in patients admitted to a rural tertiary care hospital in a high density swine region

Table 2 Estimates of associations of methicillin resistant Staphylococcus aureus nasal carriage with environmental and occupational exposures among hospitalized patients at Vidant Medical Center in eastern North Carolina, 2011

	No. (%)		Conditioned on age and gender, adjusted for education
	Controls	Cases	OR	95% CI
	(n = 119)	(n = 117)	OR	95% CI
Permitted swine per square mile of block group
0	72 (60.5)	59 (50.4)	1.00	-
>0-149	7 (5.9)	20 (17.1)	4.76	1.36-16.69
>149	40 (33.6)	38 (32.5)	0.95	0.53-1.72
Permitted farrowing swine per square mile of block group
0	87 (73.1)	77 (65.8)	1.00	-
>0-149	17 (14.3)	34 (29.1)	1.99	0.99-4.00
>149	15 (12.6)	6 (5.1)	0.42	0.15-1.13
Permitted non-farrowing swine per square mile of block group
0	77 (64.7)	70 (59.8)	1.00	-
>0-149	5 (4.2)	10 (8.6)	2.04	0.61-6.85
>149	37 (31.1)	37 (31.6)	0.95	0.54-1.68
Live within 1 mile of a concentrated animal feeding operation
No	89 (74.8)	94 (80.3)	1.00	-
Yes	30 (25.2)	23 (19.7)	0.60	0.31-1.16
Ever smell odor from a farm with animals when at home
No	97 (81.5)	86 (73.5)	1.00	-
Yes	22 (18.5)	31 (26.5)	1.51	0.80-2.86
Ever have contact with pigs, chickens, cows, or turkeys^a
No	109 (91.6)	112 (95.7)	1.00	-
Yes	10 (8.4)	5 (4.3)	0.52	0.15-1.82
Ever have contact with horses^a
No	110 (92.4)	110 (94.0)	1.00	-
Yes	9 (7.6)	7 (6.0)	0.70	0.22-2.21
Ever have contact with uncooked meat products at work or at home
No	40 (33.6)	44 (37.6)	1.00	-
Yes	79 (66.4)	73 (62.4)	0.81	0.46-1.41
Current member of the work force^b
No	70 (58.8)	80 (68.4)	1.00	-
Yes	49 (41.2)	37 (31.6)	0.74	0.41-1.33
Household members present
No	23 (19.3)	15 (12.8)	1.00	-
Yes	96 (80.7)	102 (87.2)	1.66	0.81-3.39
Live in a rural area^c
No	57 (47.9)	54 (46.1)	1.00
Yes	62 (52.1)	63 (53.9)	0.92	0.55-1.54
Human population density in block group of residence,^d mean (std)	1003.2 (1416.0)	920.7 (1346.3)	1.00	0.83-1.21

Abbreviations: odds ratio, OR; confidence interval, CI.
^aExposed category includes participants who reported direct contact outside of work and/or indirect contact at work; no participant reported direct contact at work.
^bDefined as working within the 2 weeks preceding the current hospital admission.
^cDefined based on address and using 2010 United States Census Bureau definition of rural and urban areas, with urban areas and clusters combined into a single category.
^dDefined as population/square mile in census block group of residence. Entered into the model as a linear term, and the estimate represents the odds ratio for every increase in 1,000 people/square mile.

ISSN: 1476-069X