Table 1.
Median Pneumococcal Polymerase Chain Reaction (PCR) Load (103 Copies/mL) in Whole Blood Among Children Who Were Whole-Blood PCR Positive, by Case/Control Group and Characteristic
| Characteristic | MCPP Casesa (n = 56) | Nonconfirmed Casesb (n = 3832) |
Nonconfirmed CXR+c Cases (n = 1745) |
Confirmed Nonpneumococcal Casesd (n = 107) | All Controls (n = 4987) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| PCR+, No. | Median (IQR) Loade | PCR+, No. | Median (IQR) Load | PCR+, No. | Median (IQR) Load | PCR+, No. | Median (IQR) Load | PCR+, No. | Median (IQR) Load | |
| Overall | 36 | 4.1f (1.1–77.4) | 242 | 0.29f (0.14–0.93) | 127 | 0.30f (0.14–1.0) | 12 | 1.6f (0.32–5.7) | 273 | 0.19f (0.11–0.48) |
| PERCH sites | P = .51 | P < .001 | P = .31 | P = .41 | P < .01 | |||||
| Kenya | 3 | 83.9 (4.6–419.8) | 25 | 0.17 (0.14–0.37) | 15 | 0.23 (0.12–0.48) | 3 | 0.21 (0.06–1.5) | 48 | 0.24 (0.12–0.45) |
| The Gambia | 6 | 2.2 (0.63–8.8) | 51 | 0.21 (0.11–0.52) | 20 | 0.24 (0.10–0.46) | 4 | 2.6 (1.1–7.5) | 47 | 0.23 (0.13–0.52) |
| Mali | 19 | 2.4 (0.53–96.8) | 56 | 0.59 (0.21–3.1) | 25 | 0.53 (0.17–2.1) | 2 | 43.2 (0.11–86.2) | 38 | 0.40 (0.08–1.1) |
| Zambia | 4 | 40.0 (4.1–98.9) | 37 | 0.30 (0.14–1.2) | 22 | 0.30 (0.15–1.4) | 2 | 1.6 (0.43–2.8) | 31 | 0.17 (0.11–0.38) |
| South Africa | 4 | 4.8 (1.9–20.6) | 66 | 0.27 (0.16–0.93) | 44 | 0.30 (0.16–0.94) | 1 | 7.8 (7.8–7.8) | 98 | 0.16 (0.09–0.34) |
| Bangladesh | 0 | … | 5 | 0.09 (0.06–0.30) | 1 | 25.1 (25.1–25.1) | 0 | … | 6 | 0.10 (0.06–0.10) |
| Thailand | 0 | … | 2 | 0.05 (0.01–0.09) | 0 | … | 0 | … | 5 | 0.27 (0.06–0.86) |
| Age | P = .27 | P = .57 | P = .71 | P = .35 | P = .71 | |||||
| 1–5 mo | 7 | 144.6 (1.2–731.6) | 96 | 0.25 (0.15–0.53) | 51 | 0.30 (0.17–0.53) | 3 | 0.43 (0.06–1.5) | 88 | 0.19 (0.11–0.49) |
| 6–11 mo | 10 | 2.4 (1.1–4.2) | 68 | 0.32 (0.14–1.2) | 33 | 0.30 (0.13–0.93) | 3 | 2.8 (0.21–86.2) | 72 | 0.20 (0.10–0.41) |
| 12–23 mo | 9 | 7.1 (1.8–12.1) | 52 | 0.27 (0.13–1.4) | 32 | 0.30 (0.13–1.6) | 3 | 0.49 (0.11–11.4) | 64 | 0.17 (0.11–0.33) |
| 24–59 mo | 10 | 2.1 (0.53–7.7) | 26 | 0.31 (0.13–3.8) | 11 | 1.3 (0.12–17.0) | 3 | 3.6 (1.7–7.8) | 49 | 0.19 (0.11–0.88) |
| HIV infected | P = .68 | P = .27 | P = .16 | P = .12 | P = .96 | |||||
| Yesg | 10 | 3.9 (0.53–12.1) | 24 | 0.32 (0.17–21.3) | 19 | 0.47 (0.29–25.6) | 3 | 7.8 (2.8–86.2) | 19 | 0.16 (0.11–0.46) |
| No | 23 | 2.8 (1.2–83.9) | 197 | 0.27 (0.14–0.93) | 98 | 0.28 (0.14–0.93) | 8 | 1.0 (0.27–2.6) | 224 | 0.19 (0.11–0.46) |
| Prior antibioticsh | P = .25 | P = .21 | P = .03 | P = .47 | P = .49 | |||||
| Yes | 9 | 3.9 (1.9–126.8) | 100 | 0.30 (0.15–1.1) | 64 | 0.39 (0.18–1.5) | 5 | 0.43 (0.11–3.6) | 9 | 0.23 (0.19–0.61) |
| No | 25 | 2.4 (0.73–12.1) | 131 | 0.28 (0.12–0.86) | 58 | 0.22 (0.12–0.86) | 6 | 1.6 (0.49–7.8) | 253 | 0.19 (0.11–0.47) |
| Pneumococcal NP/OP PCR load >6.9 log10 copies/mL | P = .97 | P = .03 | P = .05 | P = .10 | P = .19 | |||||
| Yes | 26 | 4.1 (0.73–96.8) | 48 | 0.46 (0.16–5.1) | 33 | 0.50 (0.16–13.1) | 3 | 7.8 (1.5–86.2) | 27 | 0.28 (0.13–0.88) |
| No | 9 | 4.6 (1.5–33.6) | 191 | 0.28 (0.14–0.67) | 92 | 0.30 (0.14–0.69) | 8 | 0.46 (0.16–3.2) | 243 | 0.18 (0.11–0.45) |
All P values obtained by Kruskal-Wallis test; P values within cells represent comparison within the case/control group for that characteristic. Bold indicates P < .05.
Abbreviations: HIV, human immunodeficiency virus; IQR, interquartile range; MCPP, microbiologically confirmed pneumococcal pneumonia; NP/OP, nasopharyngeal/oropharyngeal; PCR+, polymerase chain reaction positive for lytA gene; PERCH, Pneumonia Etiology Research for Child Health.
aMCPP defined as pneumococcus isolated from culture of blood, lung aspirate, pleural fluid, PCR of lung aspirate or pleural fluid, or detection of Streptococcus pneumoniae antigen in pleural fluid specimens on BinaxNOW.
bNonconfirmed cases defined as cases without isolation of bacteria from culture of blood, lung aspirate or pleural fluid, or PCR of lung aspirate or pleural fluid.
cCXR positive (CXR+) defined as radiographic evidence of pneumonia (consolidation and/or other infiltrates).
dConfirmed nonpneumococcal bacterial case was defined as a case with any nonpneumococcal bacterial pathogen detected by blood culture, by lung aspirate culture or PCR, or by pleural fluid culture or PCR.
eMedian load = median whole-blood lytA load (103 copies/mL) among children with PCR-positive whole-blood specimens.
f P value for MCPP vs nonconfirmed, all controls, and nonconfirmed CXR+ cases, <.001 for all; P value for MCPP vs confirmed non-pneumococcal cases, .06; P value for nonconfirmed cases vs confirmed non-pneumococcal cases, .05; P value for confirmed non-pneumococcal vs all controls, .003; P value for nonconfirmed cases vs all controls, <.001.
gControls were matched on HIV status at the 2 sites with high HIV prevalence (South Africa and Zambia).
hPrior antibiotics defined as serum bioassay positive (cases and controls), antibiotic administration at the referral facility, or antibiotic administration prior to whole-blood specimen collection at the study facility (cases only).