Table 2.
Comparison between the probability of detection of pathogens in upper and lower respiratory tract samples by PCR.
| Pathogen | U (+) L (+) | U (+) L (−) | U (−) L (+) | U (−) L (−) | Total U (+)/Total (+) | Total L (+)/Total (+) | χ2 (P-value) |
|---|---|---|---|---|---|---|---|
| A. paragallinarum | 25 | 11 | 2 | 23 | 36/38 | 27/38 | 5.94 (P = 0.015) |
| M. gallisepticum | 10 | 3 | 3 | 47 | 13/16 | 13/16 | 0.0 (P = 1.0) |
| Viruses causing IB | 5 | 6 | 2 | 48 | 11/13 | 7/13 | 1.63 (P = 0.202) |
| ORT | 1 | 2 | 0 | 60 | 3/3 | 1/3 | 0.75 (P = 0.387) |
| Any pathogen | 29 | 12 | 2 | 18 | 41/43 | 31/43 | 6.91 (P = 0.008) |
Abbreviations: IB, infectious bronchitis; L, lower; ND, Newcastle disease; ORT, Ornithobacterium rhinotracheale; U, upper.