Table 2.
Results of Comparisons of the Time Progression of Toxin-Specific Antibody Levels Among Children With Suspected Influenza Virus Monoinfection and Those Coinfected With Influenza Virus and Methicillin-Resistant Staphylococcus aureus (MRSA) or Methicillin-Susceptible S. aureus (MSSA)
| Comparison of Reciprocal Titers or IC50 Values (Log10) | MRSA Coinfection vs MSSA Coinfection | MRSA Coinfection vs Monoinfection | MSSA Coinfection vs Monoinfection |
|---|---|---|---|
| Anti-α-toxin IgG | .02 | .0007 | .29 |
| α-Toxin neutralization activity | .006 | .0001 | .12 |
| Anti-PVL LukF-PV subunit IgG | .84 | .001 | .005 |
| Anti-PVL LukS-PV subunit IgG | .07 | .0001 | .02 |
| Estimated anti-α-toxin increase | MRSA Coinfection | MSSA Coinfection | Monoinfection |
| Log10 IgG anti-α-toxin titer per unit time (95% CI) | 0.0046 (.003–.006) | 0.0017 (−2.252–2.255) | 0.0003 (−2.288–2.289) |
| Log10 IC50 α-toxin neutralization activity per unit time (95% CI) | 0.0041 (.003–.005) | 0.0014 (−2.292–2.295) | −0.0002 (−2.303–2.302) |
Data are P values unless otherwise indicated and were corrected by the Bonferroni test, with values of < .017 considered statistically significant. Analysis was done by linear mixed-effects modeling as described in “Methods” section.
Abbreviations: CI, confidence interval; IC50, half-maximal inhibitory concentration; IgG, immunoglobulin G; PVL, Panton-Valentine leukocidin.