Table 1.
Summary of virus collection frequency, concentration, and strain diversity in each of the air sampling collection sites.
| Farm | Number neighboring farms (10 km) | County density (pigs/km2) | Mean (SD) distance of the farms within 10 km | Frequency (+) samples (%) | Mean viable virus in log10 TCID50/mL (range) | Number of virus sequenced | Number of virus strains * |
|---|---|---|---|---|---|---|---|
| A | 42 | 13 | 7.53 (1.33) | 15/51 (0.29) | 4.1 (1.0–5.6) | 14 | 9 |
| B | 42 | 163 | 6.39 (2.27) | 22/53 (0.42) | 4.4 (2.0–5.0) | 12 | 9 |
| C | 20 | 221 | 6.19 (2.46) | 18/54 (0.33) | 3.8 (1.0–5.3) | 16 | 8 |
| D | 99 | 477 | 6.95 (2.17) | 25/59 (0.42) | 5.3 (3.6–6.5) | 25 | 14 |
* Strains defined by phylogenetic tree in Figure 2.