Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/24/2015
Publication Date: N/A
Technical Abstract: Newcastle disease virus (NDV) causes a range of clinical disease ranging from asymptomatic infection to severe disease with high mortality. Vaccination for NDV is practiced almost worldwide in commercial chickens. Attenuated live vaccines are most commonly used, with recombinant vaccines becoming increasingly popular. The target species for a recombinant NDV (rNDV) vaccine are poultry species. However, since NDV infects at least 250 bird species, non-target species (wild birds) could be exposed and infected with these vaccine viruses. In spite of that, the infectivity and transmissibility of rNDV vaccines have not been examined in non-poultry species. The widespread use of these vaccines and the routes of administration–which include aerosol or drinking water, pose an extremely high risk of exposure of the vaccine to wild birds. This study is part of a series of pathogenesis studies that aims to evaluate the infection and transmission of wild type and vaccine strains of NDV in non-target species. If these species can transmit the virus, this could result in the unrestricted spread of potentially pathogenic variants to other poultry farms and to wildlife. In this portion of the study, Japanese Quail are being evaluated. Quail are often kept with other poultry species, and could potentially increase transmission and magnify the outbreaks. In fact, ND outbreaks have occurred in Japanese Quail in Nigeria in 2004 and in 2008. Two experiments were conducted. The first experiment aimed to study transmission and replication of different rNDV. In this experiment, 4 week old Japanese Quail were divided into groups of 5 birds and infected with either virulent rNDV; ZJ1-L , rNDV of low virulence; ZJ1 (rZJ1-L), rNDV of the vaccine strain LaSota (rLaSota) or rNDV LaSota strain also containing the H5 avian influenza insert (rLaSota-H5) at day 0 post infection (dpi). At 2 dpi, four un-inoculated birds were placed with each group of inoculated birds. Clinical signs and mortality were recorded daily and birds were swabbed every other day until 14 dpi. The second experiment aimed to study the transmission and clinical signs caused by wild type strains of NDV. Four week old Japanese Quail were divided into groups of 7 birds, and each group was infected with either CA02, Nigeria 2, Nigeria 23, Pk/Karachi/33 or Israel/826 all wild type NDV strains. Three un-inoculated birds were placed with each of the groups at 0 dpi. Similar to the first experiment, clinical signs and mortality were recorded daily and birds were swabbed every other day until 14 dpi. Clinical disease, mortality, number of birds shedding, number of contact birds infected, amount of virus shed, and sero-conversion rates were examined.