Regional and Source Variations in Vancomycin-resistant Enterococci (VRE) Rates in US Hospitals 2015

Background: We sought to evaluate the regional differences on vancomycin-resistant enterococci(VRE) across blood, urine and wound sources.

Methods: We analyzed an electronic research dataset of Becton, Dickinson & Company from 346 USA hospitals in 2015. All non-duplicate Enterococciisolates (first isolate of a species per 30 day period) from blood, urine, and wound were categorized as VRE if confirmed as intermediate/resistant to vancomycin. Positive isolates were categorized by specimen collection location as: a) Ambulatory: if collected in non-inpatient setting; b) Inpatient: if collected during an inpatient stay. Geographic regions were classified into 10 NHSN categories (Sievert, 2013, ICHE). Region 1, 7, and 8 were grouped into “Other” due to small numbers of hospitals. We conducted pairwise comparisons with Bonferroni correction between regions within each setting using the region with the overall lowest VRE rate as the reference group.

Results: The overall VRE rate was 15.2% (19650/129407). The setting specific VRE rates were 9.7% (7116/73732), and 22.5% (12534/55675) for ambulatory and inpatient, respectively. For regional differences in the ambulatory setting all were significant when compared to Region 10 except for wound source Regions 5 and Other. For regional differences in the inpatient setting all were significant except for blood Regions 3, 4 and Other.

Region (# of Hospitals)	States	% VRE Ambulatory*			% VRE Inpatient*
		Blood	Urine	Wound	Blood	Urine	Wound
2 (30)	NJ, NY, PR, VI	16.6	10.3	13.6	39.4	27.1	22.6
3 (13)	DE, DC, MD, PA, VA, WV	20.2	11.5	11.1	27.5	24.4	19.7
4 (98)	AL, FL, GA, KY, MS, NC, SC, TN	13.0	8.1	6.1	23.5	18.1	17.2
5 (85)	IL, IN, MI, MN, OH, WI	19.6	11.3	9.9	39.7	27.3	25.7
6 (59)	AR, LA, NM, OK, TX	19.9	10.9	10.7	26.9	20.9	17.5
9 (28)	AZ, CA, HI, Pacific Islands	13.1	8.6	10.4	40.1	24.0	25.2
10 (22)	AK, ID, OR, WA	0.7	3.2	4.6	13.9	9.0	8.3
Other (11)	All Other	13.6	5.4	3.3	23.0	16.5	15.2
All Regions		16.1	9.5	9.1	31.3	22.2	20.5

* P < 0.007 for all sources compared to Region 10 except for ambulatory wound Regions 4, 5 and inpatient blood Regions 3, 4 and Other

Conclusion: The vancomycin-resistant Enterococci rate was more than twice as high in the inpatient setting as in ambulatory setting. The majority of regions showed significant differences within sources.