Investigation of lung lesions in parainfluenza-3 infections in ruminants by pathological and immunohistochemical methods

Parainfluenza 3 infection is one of the most common viral infections among respiratory system diseases of domestic and wild ruminants. The disease is more common in the presence of poor maintenance and feeding conditions, transport, and concomitant viral and bacterial infections. The most common finding in the disease is characterized bronchointerstitial pneumonia. Concomitant viral and bacterial infections may increase severity of lesions and cause it to turn into fibrinopurulent-necrotic bronchopneumonia. The aim of this study is to examine the histopathological findings of PI3 infection in ruminants and the release of Mannose Binding Lectin (MBL) and Surfactan B in the lung tissue during inflammation, their role and importance in pathogenesis and their relationships each other. For this purpose, paraffin-blocked tissues of 30 ruminant lungs with suspected viral pneumonia and 10 without lesions were used. Histopathologically, in the sections taken, acute destructive stage was observed in most of the cases (78%), and chronic proliferative stage in 4 patients (22%). As a result of the applied immunohistochemical methods, anti-PI3 positive (50%) findings were found in 15 animals. However, it was determined that MBL release was high in inflammatory reactions of tissues in acute cases, but decreased in subacute or chronic cases. SP-B release was increased in subacute or chronic cases rather than acute cases. As a result, it was thought that in cases of immune deficiency or mixed infection, MBL release is insufficient for recovery, and if it is treated early and correctly, the possibility of survival of animals may increase thanks to SP-B.