TABLE 1.
Clinical and bacterial characteristics of MRSA bloodstream infection by cytotoxicity categorya
| Characteristic | Data for: |
P value | ||
|---|---|---|---|---|
| Total (n = 776) | High-cytotoxicity group (n = 194) | Low-cytotoxicity group (n = 582) | ||
| Avg age (median [yrs]) | 62 (62) | 63 (62) | 62 (62) | 0.62 |
| Age > 65 yrs | 341 (44) | 86 (44) | 255 (44) | 0.90 |
| Male sex | 450 (58) | 109 (56) | 341 (59) | 0.56 |
| Hospital-onset infection | 249 (32) | 58 (30) | 191 (33) | 0.45 |
| Community-onset infection | 527 (68) | 136 (70) | 391 (67) | 0.45 |
| PBS (avg [median]) | 2.7 (2.0) | 2.8 (2.0) | 2.6 (2.0) | 0.77 |
| PBS ≥ 4 | 208 (27) | 53 (27) | 155 (27) | 0.94 |
| Comorbidities | ||||
| Avg CCI (median) | 4.1 (4.0) | 3.9 (4.0) | 4.2 (4.0) | 0.35 |
| CCI ≥ 3 | 529 (68) | 128 (66) | 401 (69) | 0.45 |
| Diabetes | 81 (10) | 22 (11) | 59 (10) | 0.64 |
| Prior MI/CAD | 27 (3.5) | 5 (2.6) | 22 (3.8) | 0.43 |
| Peripheral vascular disease | 85 (11) | 23 (12) | 62 (11) | 0.64 |
| Chronic heart failure | 104 (13) | 25 (13) | 79 (14) | 0.81 |
| Chronic kidney disease | 220 (28) | 51 (26) | 169 (29) | 0.46 |
| ESRD/dialysis | 106 (14) | 23 (12) | 83 (14) | 0.40 |
| Liver disease | 64 (8.3) | 20 (10) | 44 (7.6) | 0.23 |
| Chronic pulmonary disease | 91 (12) | 21 (11) | 70 (12) | 0.65 |
| Connective tissue disease | 2 (0.26) | 0 (0) | 2 (0.34) | 0.41 |
| HIV | 73 (9.4) | 13 (6.7) | 60 (10) | 0.14 |
| Cerebrovascular disease | 8 (1.0) | 1 (0.52) | 7 (1.2) | 0.41 |
| Hemiplegia/paraplegia | 15 (1.9) | 2 (1.0) | 13 (2.2) | 0.29 |
| Malignancy | 67 (8.6) | 17 (8.7) | 50 (8.6) | 0.94 |
| Chemotherapy | 51 (6.6) | 12 (6.2) | 39 (6.7) | 0.80 |
| Infective source | ||||
| Pneumonia | 140 (18) | 32 (16) | 108 (19) | 0.52 |
| Skin and soft tissue infection | 136 (17) | 45 (23) | 91 (16) | 0.02 |
| Bone/joint | 56 (7.2) | 11 (5.7) | 45 (7.7) | 0.34 |
| Catheter related | 153 (20) | 35 (18) | 118 (20) | 0.50 |
| Device related | 8 (1.0) | 4 (2.1) | 4 (0.7) | 0.10 |
| Surgical site | 51 (6.6) | 10 (5.2) | 41 (7.0) | 0.36 |
| Endovascular | 57 (7.4) | 13 (6.7) | 44 (7.6) | 0.69 |
| Other | 12 (1.6) | 5 (2.6) | 7 (1.2) | 0.18 |
| Unknown | 163 (21) | 39 (20) | 124 (21) | 0.72 |
| Infectious disease consult | 323/508 (64) | 84/150 (56) | 239/358 (67) | 0.02 |
| MRSA treatment during hospital stay | 743 (96) | 187 (96) | 556 (96) | 0.61 |
| Duration of BSI | ||||
| ≥3 days | 248 (32) | 65 (34) | 183 (31) | 0.59 |
| ≥5 days | 136 (18) | 42 (22) | 94 (16) | 0.08 |
| ≥10 days | 36 (4.6) | 8 (4.1) | 28 (4.8) | 0.69 |
| Avg length of admission (days) | 26 | 23 | 27 | 0.10 |
| Antibiotic susceptibility | ||||
| Vancomycin MIC, geometric mean | 1.37 | 1.44 | 1.34 | 0.02 |
| Vancomycin MIC ≥ 1.5 | 332 (43) | 93 (48) | 239 (41) | 0.09 |
| Genotype by spa-CC group | ||||
| spa-CC002/ST5 | 335 (43) | 46 (24) | 289 (50) | <0.01 |
| spa-CC008/ST8 | 381 (49) | 137 (71) | 244 (42) | |
| agr defective | 243/772 (31) | 45/194 (23) | 198/578 (34) | <0.01 |
| Mortality | ||||
| 30-day mortality | 198 (26) | 45 (23) | 153 (26) | 0.39 |
a
Data represent number and percentage in parentheses unless otherwise specified. Abbreviations: CCI, Charlson comorbidity index; MI/CAD, myocardial infarction/coronary artery disease; ESRD, end-stage renal disease; HIV, human immunodeficiency virus; BSI, bloodstream infection.