Table 1.
Demographic, clinical, and laboratory characteristics of COVID-19 patients with bacterial superinfection compared to those with negative lower respiratory culture (LRCx).
| Variables shown as median (IQR) except where otherwise specified | Pure viral infection (n = 100) |
Bacterial superinfection (n = 85) |
p-value |
|---|---|---|---|
| Age, median (IQR) | 64.50 (55.00, 76.25) | 63.00 (49.00, 69.00) | 0.128 |
| Female sex, n (%) | 34 (34.0%) | 23 (27.1%) | 0.308 |
| Body mass index | 28.22 (23.92, 35.78) | 30.28 (25.63, 36.14) | 0.353 |
| ICU admission, n (%) | 84 (84.0%) | 75 (88.2%) | 0.409 |
| Mechanical ventilation, n (%) | 57 (57.0%) | 68 (80.0%) | <0.001 |
| Renal failure, n (%) | 67 (67.0%) | 65 (76.5%) | 0.156 |
| Shock, n (%) | 73 (73.0%) | 66 (79.5%) | 0.304 |
| Mortality, n (%) | 22 (22.0%) | 28 (32.9%) | 0.095 |
| Steroids within 24 h of LRCx, n (%) | 22 (22.0%) | 23 (27.1%) | 0.424 |
| Tocilizumab within 14d of LRCx, n (%) | 67 (67.0%) | 47 (55.3%) | 0.103 |
| Biomarkers at time of LRCx | |||
| PCT | 0.40 (0.13, 0.76) | 0.30 (0.14, 0.88) | >0.999* |
| WBC | 8.30 (4.80, 13.60) | 10.20 (6.00, 14.10) | >0.999* |
| Creatinine | 1.23 (0.82, 2.48) | 1.06 (0.71, 1.79) | >0.999* |
| C-reactive protein | 91.85 (30.08, 153.47) | 49.75 (15.05, 108.25) | 0.289 |
| D-Dimer | 2.02 (1.13, 5.00) | 2.59 (0.93, 4.61) | >0.999* |
| Ferritin | 1143.00 (653.50, 1982.25) | 816.00 (332.50, 1689.75) | 0.210 |
| Temperature | 98.20 (97.80, 99.23) | 98.90 (98.00, 99.75) | 0.156 |
| Microbiological data | Count | ||
| Staphylococcus aureus, n (%) | 34 (34.7%) | ||
| Methicillin-resistant S. aureus, n (%) | 6 (6.1%) | ||
| Pseudomonas aeruginosa, n (%) | 12 (12.2%) | ||
| Haemophilus influenzae, n (%) | 8 (8.2%) | ||
| Klebsiella pneumoniae, n (%) | 7 (7.1%) | ||
| Enterobacter spp, n (%) | 7 (7.1%) | ||
| Escherichia coli, n (%) | 6 (6.1%) | ||
| Beta-hemolytic streptococcus, n (%) | 5 (5.1%) | ||
| Moraxella catarrhalis, n (%) | 4 (4.1%) | ||
| Other bacterial pathogens†, n (%) | 9 (9.2%) | ||
| Polymicrobial infection, n (%) | 13 (15.3%) |
*Bonferroni-adjusted p-values are reported for biomarkers to adjust for multiple comparisons.
†Other bacterial pathogens include species observed < 3 times. These include Streptococcus pneumoniae (2), Serratia marcescens (2), Stenotrophomonas maltophilia (2), Citrobacter koseri (1), Morganella morganii (1), Proteus mirabilis (1).
p-values were calculated via chi-squared test or Kruskal-Wallis test, as appropriate.
Abbreviations: intensive care unit (ICU), lower respiratory culture (LRCx), interquartile range (IQR), procalcitonin (PCT), white blood cell count (WBC).