A STUDY ON HISTOPATHOLOGIC CHANGES IN CHICKEN FOLLOWING INTRAVENOUS INOCULATION WITH AVIAN INFLUENZA VIRUS A/CHICKEN/IRAN/259/1998(H9N2)

Summary To determine the type, severity and frequency of gross, histopathologic changes and tissue tropism of avian influenza virus (AIV) a group of twenty, 5-week-old chickens (hatched from SPF eggs) were inoculated intravenously (IV) with type A AIV [A/Chicken/Iran/259/1998(H9N2)]. Another twenty chickens were inoculated IV with sterile chorioallantoic fluid (CAF). Tubulointerstitial nephritis and pancreatitis were the most frequent specific histopathologic changes. Influenza nucleoprotein was demonstrated in renal tubule epithelium and in acini of pancreas/foci of necrosis in both organs .The virus was localized in cytoplasm and nuclei of proximal/distal tubule epithelium. Common nonspecific histopathologic changes were lymphoid and reticuloendothelial cell hyperplasia in spleen, leukocyte cell infiltration in myocardium and lymphocyte infiltration in liver. The results indicate that the low pathogenic AIV isolate was epithliotropic in chicken.