Table 4. Frequency and distribution pattern of recorded histological features in wild boar lungs.
| Bronchi and bronchioles | Alveolar parenchyma and/or interstitium | |||
|---|---|---|---|---|
| Histological features | PCR-positive N (%) | PCR-negative N (%) | PCR-positive N (%) | PCR-negative N (%) |
| BALT hyperplasia a | 53 (50.0) | 24 (22.6) | - | - |
| Infiltration of histiocytes | 44 (41.5) | 24 (22.6) | 57 (53.7) | 35 (33.0) |
| Infiltration of lymphocytes | 40 (37.7) | 23 (21.6) | 31 (29.2) | 26 (24.5) |
| Infiltration of plasma cells | 22 (20.7) | 7 (6.6) | 27 (25.4) | 2 (1.8) |
| Infiltration of neutrophils | 17 (16.0) | 0 | 13 (12.2) | 1 (0.9) |
| Infiltration of eosinophils b | 33 (31.1) | 24 (22.6) | 9 (8.4) | 12 (11.3) |
| Perivascular infiltration | - | - | 44 (41.5) | 25 (23.5) |
| Intralesional parasites | 21 (19.8) | 16 (15.0) | 24 (22.6) | 18 (16.9) |
| Intralesional bacteria or fungal organisms | 0 | 0 | 0 | 0 |
| Intraalveolar edema c | - | - | 22 (20.7) | 5 (4.7) |
| Mean number of lymphoid follicles in hyperplastic BALT | 2.8 | 1.1 | - | - |
| Cellularity of cut section (%) | - | - | Low (37.7), Moderate (44.3), High (17.9) | |
| Overall distribution pattern of infiltrate (%) | Focal (5.6%), Multifocal (87.7%), Diffuse (1.8%) | Multifocal (89.6%), Focal (1.8%), Diffuse (8.4%) | ||
a BALT hyperplasia with active follicles was not associated with the presence of parasites (p-value = 0.3697).
b Eosinophil infiltration in the airways was associated with the presence of intralesional parasites (p-value = 0.0002).
c Intra-alveolar edema was associated with plasma cell clusters in the interstitium (p-value = 0.0004), parasites (p-value = 0.0467) and neutrophils in the alveolar parenchyma and/or interstitium (p-value = 0.0467). Observations are classified according to the concerned anatomic structure and the PCR results obtained with bronchial swabs. A total of 106 lungs were examined.