Table 3.
Patient demographic and clinical characteristics of MRSA subgroups by swine livestock exposure quartilea [data are n (%) unless otherwise indicated]
| Characteristic | CO-PVL-negative (n = 23)b | scn-negative (n = 15)b | All other MRSA (n = 162) | Swine (quartile) | |||
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | ||||
| Sex, male | 15 (65.2) | 11 (73.3) | 85 (52.5) | 28 (26.2) | 25 (23.4) | 24 (22.4) | 30 (28.0) |
| Age at infection or visit [median (interquartile range)] (years) | 54.2 (32.3–75.2) | 52.8 (14.6–75.1) | 32.8 (14.4–55.2) | 46.0 (17.3–62.4) | 33.6 (22.5–54.7) | 31.1 (9.8–51.7) | 37.5 (13.6–59.1) |
| Race/ethnicityc | |||||||
| Non-Hispanic white | 22 (95.7) | 15 (100) | 155 (95.7) | 44 (23.4) | 49 (26.1) | 48 (25.5) | 47 (25.0) |
| Non-Hispanic black | 1 (4.4) | 0 | 6 (3.7) | 5 (71.4) | 0 | 0 | 2 (28.6) |
| Other | 0 | 0 | 1 (0.6) | 0 | 0 | 1 (100) | 0 |
| Never-smoker | 16 (69.6) | 10 (66.7) | 139 (85.8) | 39 (23.9) | 43 (26.4) | 40 (24.5) | 41 (25.2) |
| Season of onset | |||||||
| Winter | 7 (30.4) | 3 (20.0) | 27 (16.7) | 12 (34.3) | 7 (20.0) | 7 (20.0) | 9 (25.7) |
| Spring | 5 (21.7) | 4 (26.7) | 37 (22.8) | 16 (34.8) | 13 (28.3) | 9 (19.6) | 8 (17.4) |
| Summer | 7 (30.4) | 5 (33.3) | 39 (24.1) | 10 (20.4) | 16 (32.7) | 12 (24.5) | 11 (22.5) |
| Autumn | 4 (17.4) | 3 (20.0) | 59 (36.4) | 11 (16.7) | 13 (19.7) | 21 (31.8) | 21 (31.8) |
| Antibiotic prescription in previous year | 5 (21.7) | 6 (40.0) | 65 (40.1) | 21 (27.6) | 20 (26.3) | 15 (19.7) | 20 (26.3) |
| Source | |||||||
| Skin/soft tissue | 19 (82.6) | 11 (73.3) | 141 (87.0) | 36 (25.9) | 39 (28.1) | 28 (20.1) | 36 (25.9) |
| Respiratory | 0 | 2 (13.3) | 15 (9.3) | 6 (35.3) | 4 (23.5) | 4 (23.5) | 3 (17.7) |
| Bone | 2 (8.7) | 1 (6.7) | 2 (1.2) | 1 (25.0) | 0 | 2 (50.0) | 1 (25.0) |
| Other | 2 (8.7) | 1 (6.7) | 4 (2.5) | 0 | 3 (42.9) | 2 (28.6) | 2 (28.6) |
| Antibiotic resistanced | |||||||
| Clindamycin | 12 (52.2) | 2 (13.3) | 32 (19.8) | 10 (21.7) | 11 (23.9) | 13 (28.3) | 12 (26.1) |
| Erythromycin | 18 (78.3) | 12 (80.0) | 149 (92.0) | 43 (24.4) | 46 (26.1) | 46 (26.1) | 41 (23.3) |
| Tetracycline | 4 (17.4) | 1 (6.7) | 4 (2.5) | 2 (25.0) | 2 (25.0) | 2 (25.0) | 2 (25.0) |
| TMP-SMZ | 1 (4.4) | 1 (6.7) | 2 (1.2) | 2 (66.7) | 1 (33.3) | 0 | 0 |
| Multidruge | 14 (60.9) | 3 (20.0) | 33 (20.4) | 12 (24.5) | 11 (22.5) | 14 (28.6) | 12 (24.5) |
| Community type | |||||||
| City | 1 (4.4) | 0 | 23 (14.2) | 11 (45.8) | 3 (12.5) | 9 (37.5) | 1 (4.2) |
| Borough | 11 (47.8) | 5 (33.3) | 44 (27.2) | 15 (25.9) | 15 (25.9) | 8 (13.8) | 20 (34.5) |
| Township | 11 (47.8) | 10 (66.7) | 95 (58.6) | 23 (20.2) | 31 (27.2) | 32 (28.1) | 28 (24.6) |
| Medical Assistance | |||||||
| Never received | 15 (65.2) | 10 (66.7) | 127 (78.4) | 35 (23.3) | 37 (24.7) | 41 (27.3) | 37 (24.7) |
| Location of onset | |||||||
| Community | 27 (100) | 15 (83.3) | 135 (83.3) | 41 (24.7) | 43 (25.9) | 40 (24.1) | 42 (25.3) |
| Hospital | 0 | 3 (16.7) | 27 (16.7) | 8 (26.7) | 6 (20.0) | 9 (30.0) | 7 (23.3) |
| No. of patients with high-density livestock production in their residential ZIP code | 9 (39.1) | 7 (46.7) | 67 (41.4) | 1 (1.2) | 17 (21.0) | 25 (30.9) | 38 (46.9) |
| Abbreviations: previous year, 365 to 14 days before infection; TMP-SMZ, trimethoprim– sulfamethoxazole.aQuartile 1: swine livestock exposure < 6.20 AEU/km2; quartile 2: 6.20–16.00 AEU/km2; quartile 3: 16.01–33.40 AEU/km2; quartile 4: > 33.41 AEU/km2. bFour patients were in both the CO-PVL-negative group and the scn-negative group. cRace/ethnicity was missing for two members of the all other MRSA isolates comparison group. dResistance to gentamicin was observed in one CO-PVL-negative isolate, and intermediate resistance to rifampin was observed in one all other MRSA isolates. eResistance to three or more unique antimicrobials. | |||||||