Table 2. Influenza A positive samples by electrical impedance and RT-PCR assays from preschool.
| Control | Humidified | Control vs. humidified | ||||
|---|---|---|---|---|---|---|
| SampleType | Assay | %positive | n | %positive | n | OR, [95% CI], P> |z| |
| Mixed (fomites and air) | Electrical impedance | 48.1 | 27 | 16.7 | 18 | LCSα |
| Mixed (fomites and air) | PCR | 20 | 320 | 14.5 | 330 | LCSα |
| Fomites | PCR | 22.1 | 140 | 18.0 | 150 | 0.51, [0.33–0.78], 0.002 |
| Air (total) | PCR | 18.3 | 180 | 11.7 | 180 | 0.51, [0.29–0.89], 0.020 |
| Air <1 μm | PCR | 13.3 | 60 | 10.0 | 60 | 1.25, [0.91–1.72], 0.174 |
| Air 1–4 μm | PCR | 25.0 | 60 | 16.7 | 60 | 0.48, [0.16–1.42], 0.183 |
| Air >4 μm | PCR | 16.7 | 60 | 8.3 | 60 | 0.51, [0.23–1.10], 0.087 |
Percentage positive were calculated by dividing the number of positive samples by the number of samples taken in that condition. The sample number (n) is indicated. Samples tested by PCR included all fomites and air samples and are shown combined and separated into fomite and air (total) categories. Additionally air samples were separated into the three sizes of air particles collected. Statistical analyses of OR, 95% CI and P>|z| are indicated. α Indicates low cell size (LCS) so statistical analyses not run due to small sample size.