Table 4. Associations between reported work activities and carriage of MDRSA and tetracycline-resistant scn-negative S. aureus CC398 among ILO workers^a carrying S. aureus.

		Total	MDRSA			Tetracycline-resistant scn-negative S. aureus CC398 b
		N = 34	N = 13	Prevalence	PR (95% CI)	N = 11	Prevalence	PR (95% CI)
Direct contact with pigs
	No	6	2	33.3	Ref	1	16.7	Ref
	Yes	28	11	39.3	1.2 (0.3, 4.4)	10	35.7	2.1 (0.3, 14.4)
Direct contact with poultry
	No	28	11	39.3	Ref	10	35.7	Ref
	Yes	6	2	33.3	0.8 (0.2, 3.1)	1	16.7	0.5 (0.1, 3.1)
Were cut/scratched while in direct contact with livestock
	No	22	9	40.9	Ref	8	36.4	Ref
	Yes	12	4	33.3	0.8 (0.3, 2.0)	3	25.0	0.7 (0.2, 2.2)
Draw blood/collect fluids from pigs
	No	27	8	29.6	Ref	10	37.0	Ref
	Yes	7	5	71.4	2.4 (1.1, 5.1)	1	14.3	0.4 (0.1, 1.9)
Work with breeding pigs
	No	23	6	26.1	Ref	5	21.7	Ref
	Yes	11	7	63.6	2.4 (1.0, 5.7)	6	54.5	2.5 (1.0, 6.4)
Handle livestock that were dead
	No	5	2	40	Ref	3	60.0	Ref
	Yes	29	11	37.9	0.9 (0.3, 3.1)	8	27.6	0.5 (0.2, 1.1)

ILO = industrial livestock operation.

PR = Prevalence ratio.

^aAssociations among AFLO workers are not presented due to small numbers of reported activities in the group who carried S. aureus.

^bDue to overlap among tetracycline-resistance, scn-negative, and CC398 isolates and similarity of estimates, we present prevalence ratios and 95% confidence intervals for tetracycline-resistant scn-negative S. aureus CC398.