Table 2.
Laboratory findings for patients with invasive and noninvasive skin and soft tissue infections caused by group A Streptococcus
| Laboratory findings | No. of patients (%) witha: |
Odds ratio (95% CI)b | P valueb | |
|---|---|---|---|---|
| Invasive SSTI | Noninvasive SSTI | |||
| White blood cell count ≥ 11,000 cells/mm3 | 27/34 (79.4) | 16/25 (64) | 2.17 (0.68–6.96) | 0.188 |
| Neutrophil percentage ≥ 80 | 25/31 (80.6) | 12/25 (48) | 4.51 (1.38–14.8) | 0.01 |
| Band percentage ≥ 5 | 5/31 (16.1) | 0/25 (0) | 0.058 | |
| Hemoglobin level ≤ 10 g/dl | 7/34 (20.6) | 1/25 (4) | 6.22 (0.71–54.29) | 0.122 |
| Platelet count ≤ 100,000 cells/mm3 | 5/34 (14.7) | 2/25 (8) | 1.98 (0.35–11.17) | 0.687 |
| Blood urea nitrogen level ≥ 40 mg/dl | 8/25 (32) | 1/13 (7.7) | 5.65 (0.62–51.29) | 0.126 |
| Creatinine level ≥ 2 mg/dl | 12/32 (37.5) | 2/19 (10.5) | 5.1 (1–26.05) | 0.037 |
| Aspartate aminotransferase level ≥ 80 U/liter | 5/27 (18.5) | 1/16 (6.3) | 3.41 (0.36–32.19) | 0.386 |
| Alanine aminotransferase level ≥ 80 U/liter | 4/26 (15.4) | 2/12 (16.7) | 0.91 (0.14–5.81) | 0.999 |
| Glucose level ≥ 200 mg/dl | 9/27 (33.3) | 3/13 (23.1) | 1.67 (0.37–7.61) | 0.716 |
| Creatinine phosphokinase level ≥ 600 U/liter | 2/9 (22.2) | 1/2 (50) | 0.29 (0.01–6.91) | 0.491 |
| C-reactive protein level (mg/liter) (mean ± SD)c | 205.4 ± 161.6 | 77.5 ± 79.3 | 0.002 | |
a
The number of patients with a positive result for the laboratory finding/total number of patients in each group (percentage) is shown unless specified otherwise (i.e., C-reactive protein).
b
The odds ratio (95% confidence interval [95% CI]) and P value for patients with invasive and noninvasive SSTIs are shown.
c
The mean C-reactive protein level ± standard deviation (SD) for 39 patients is shown.