Pigeon Paramyxovirus: Association with Common Avian Pathogens in Chickens and Serologic Survey in Wild Birds

Abstract

Pigeon paramyxovirus-1 (PPMV-1) was isolated from pigeons from east-central Alabama and used in association with chicken anemia virus (CAV), infectious bursal disease virus (IBDV), or finch Mycoplasma gallisepticum (MG) in specific-pathogen-free chickens to assess dinical disease and pathology. PPMV-1 infection in all groups was conducted at day 10 of age via the ocular route. The low passage PPMV-1 isolate was inoculated into chickens in different groups at 10 days post-CAV infection, 6 days post-IBDV infection, and 6 days post-finch MG infection, respectively. Additionally, to obtain information on the status of paramyxovirus infection in the wild bird population of the region, we used a multispecies competitive enzyme-linked immunosorbent assay kit to assess serum samples from 180 wild birds representing 24 species obtained throughout 2001. Mild respiratory signs characterized by sneezing were observed in PPMV-1-infected chicks. In the brain, PPMV-1 caused disseminated vasculitis in the neuropile and meninges, sometimes with small foci of gliosis. Most brains had only mild lesions. In the upper respiratory tract, lesions were confined to the larynx and proximal trachea as hyperplasia of laryngeal mucosa-associated lymphoid tissue. In the lung, PPMV-1 caused minimal to moderate multifocal interstitial pneumonia. Lymphocytic expansion occurred in the interstitium of the Harderian gland. PPMV-1 in the spleen caused expansion of the white pulp as a result of hypertrophy of the macrophages in the periarteriolar sheaths accompanied by lymphocytic hyperplasia at the periphery. No severe aggravation of either signs or lesions could be attributed to any of the avian pathogens used in association with PPMV-1. The serologic survey in wild birds showed antibody levels that were considered negative or doubtful. Interestingly, significantly (P < 0.05) higher mean titers were observed during the months of October and November 2001, following closely multiple PPMV-1 episodes of mortality in wild collard doves in northwestern Florida.