Table 3.
Prevalence of Bacteria Cultured as the Predominant Organism With Compatible Gram Stain From High-Quality Induced Sputum Among Radiographic Pneumonia Cases and Nonpneumonia Cases, by Antibiotic Exposure Status
| Regardless of Antibiotic Exposure a | No Antibiotic Exposure | Antibiotic Exposure | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Bacteria | CXR+ b (N = 1162) n (%) | Nonpneumoniac(N = 398) n (%) | P Value d | CXR + (N = 219) n (%) | Nonpneumonia (N = 124) n (%) | P Value | CXR + (N = 908) n (%) | Nonpneumonia (N = 266) n (%) | P Value |
| Streptococcus pneumoniae | 240 (20.7) | 94 (23.6) | .23 | 90 (41.1) | 55 (44.4) | .57 | 139 (15.3) | 37 (13.9) | .63 |
| Staphylococcus aureus | 29 (2.5) | 9 (2.3) | >.99 | 3 (1.4) | 4 (3.2) | .26 | 26 (2.9) | 5 (1.9) | .52 |
| Other streptococci and enterococci e | 5 (0.4) | 2 (0.5) | >.99 | 2 (0.9) | 1 (0.8) | >.99 | 3 (0.3) | 1 (0.4) | >.99 |
| Haemophilus influenzae | 262 (22.5) | 92 (23.1) | .84 | 104 (47.5) | 60 (48.4) | .91 | 141 (15.5) | 27 (10.2) | .03 |
| Moraxella catarrhalis | 215 (18.5) | 93 (23.4) | .04 | 62 (28.3) | 29 (23.4) | .37 | 147 (16.2) | 61 (22.9) | .01 |
| Enterobacteriaceae f | |||||||||
| All | 34 (2.9) | 11 (2.8) | >.99 | 1 (0.5) | 1 (0.8) | >.99 | 32 (3.5) | 10 (3.8) | .85 |
| Klebsiella pneumoniae | 19 (1.6) | 6 (1.5) | >.99 | 1 (0.5) | 0 (0.0) | >.99 | 17 (1.9) | 6 (2.3) | .62 |
| Mixed gram-negative rods | 16 (1.4) | 2 (0.5) | .27 | 2 (0.9) | 0 (0.0) | .54 | 12 (1.3) | 2 (0.8) | .75 |
| Other nonfermentative gram-negative rods g | |||||||||
| All | 8 (0.7) | 7 (1.8) | .07 | 0 (0.0) | 2 (1.6) | .13 | 8 (0.9) | 5 (1.9) | .19 |
| Pseudomonas aeruginosa | 4 (0.3) | 3 (0.8) | .38 | 0 (0.0) | 0 (0.0) | N/A | 4 (0.4) | 3 (1.1) | .20 |
High-quality induced sputum defined as <10 epithelial cells per low-power field.
Abbreviation: CXR, chest radiograph.
aPrior use of antibiotics defined as bioassay positive, antibiotic administration at the referral facility, antibiotic administration prior to induced sputum specimen collection at the study facility.
bRadiographic pneumonia (CXR+) defined as any abnormal CXR (consolidation and/or other infiltrates).
cNonpneumonia case defined as a case with a normal CXR, blood culture pathogen negative, and normal respiratory rate or nonhypoxic in the absence of crackles, or normal respiratory rate and nonhypoxic in the presence of crackles.
d P value from χ2 or Fisher exact test.
eOther streptococci and enterococci includes Streptococci (other than S. pneumoniae) and Enterococci species.
fEnterobacteriaceae includes Escherichia coli, Enterobacter species, Klebsiella species, Citrobacter species, and Serratia species, excluding mixed gram-negative rods. Klebsiella pneumoniae also reported separately.
gOther nonfermentative gram-negative rods include Pseudomonas aeruginosa, Acinetobacter species, Pseudomonas species. Pseudomonas aeruginosa also reported separately.