Title: Newcastle disease B1 vaccine strain in wild rock pigeons in Atlanta, Georgia Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 2014
Publication Date: N/A
Technical Abstract: From June to October of 2012, samples were collected from wild Rock Pigeons (Columba livia) in urban neighborhoods of Atlanta, Georgia to ascertain the prevalence of pigeon paramyxovirus serotype-1 (PPMV-1). PPMV-1 strains are a subset of avian paramyxovirus serotype-1 (APMV-1) commonly isolated from pigeons, primarily affecting the neurological system. APMV-1 is highly contagious, and infection with a virulent strain causes Newcastle disease (ND) that is spread to other susceptible birds through contact with virus infected saliva and feces. While antibodies for APMV-1 were found in 66% of tested Rock Pigeons within the metro Atlanta area in a 2002 study, only 5.63% of the serum from 71 Rock Pigeons tested positive for hemagglutination inhibition for AMPV-1 in this 2012 study. Virus isolation of oral and cloacal swabs from 41 pigeons in SPF embryonating chicken eggs was performed. Swabs positive for hemagglutination underwent RNA extraction for RT-PCR. Data from sequencing complementary DNA (cDNA) using APMV-1 fusion gene specific primers underwent phylogenetic analysis and genotype identification. About 15% of the pigeons actively shed virus at the time of capture, which was identified as the APMV-1 B1 strain poultry vaccine, as opposed to the expected PPMV-1 strains. Moreover, the presence of the APMV-1 strain vaccine strain was negatively correlated with pigeon condition, measured as the weight-to-wing chord ratio and mean retrix growth bar width. Since the B1 vaccine is not normally used for pigeons these results suggest that improper vaccination practices in poultry and/or lack of biosecurity measures to prevent contact with free-ranging, susceptible avian species may release live vaccines into the environment. The association between reduced weight and infection may be explained by unthriftiness and poor feed conversion in wild birds due to immunological energetic reallocation. The escape of live Newcastle disease virus (APMV-1) vaccines into the environment need to be further studied as it may have far-ranging ecological and economic implications.