Submitted to: Epidemiology and Infection
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/30/2002
Publication Date: 4/1/2004
Citation: O'Donoghue, K., Lomniczi, B., Mcferran, B., Connor, T.J., Seal, B.S., King, D.J., Banks, J., Manville, R., White, S., Richmond, K., Jackson, P., Hugh-Jones, M. 2004. Retrospective Characterization Of Newcastle Disease Virus Antrim '73 In Relation To Other Epidemics, Past And Present. Epidemiology And Infection. 2004, v.132, p.357-368. Interpretive Summary: Newcastle disease virus may cause an acute systemic disease among commercial poultry, especially chickens. Although the vaccine is protective against disease, outbreaks continue to occur worldwide. When highly virulent forms of Newcastle disease erupt among commercial poultry it is required that these outbreaks be reported to national and international agricultural authorities. During the early 1970's highly virulent Newcastle disease occurred at several locations around the world at approximately the same time. Consequently, nucleotide sequences from the genomes of viruses isolated in Northern Ireland during outbreaks of severe disease during 1973 were compared to virus isolates obtained from other geographical locations. This was accomplished by a retrospective analysis utilizing diagnostic samples stored since then. The Newcastle disease outbreak was linked to imported parrots and was apparently spread by feed stuffs that had been contaminated by pigeon feces when pigeons had also contracted Newcastle disease virus.
Technical Abstract: In November 1973 Newcastle disease appeared in Northern Ireland, where the viscerotropic disease had not been detected for three years and the two Irelands had been regarded as essentially disease free for thirty years. The outbreak was controlled with only 36 confirmed affected layer flocks plus 10 more slaughtered as "dangerous contacts." Contemporary investigations failed to reveal the source of the Irish epidemic. Using archival virus samples from most of the affected flocks, RT-PCR was conducted with primers selected for all six Newcastle disease virus genes. Phylogenetic analyses of three genes, HN, M and F, confirmed the vaccine cause of one of the outbreaks. The other six samples were identical and closely related to previous outbreaks in the USA and Western Europe initiated by infected imported Latin American parrots. The probable cause of the epidemic followed from the importation from The Netherlands of bulk feed grains contaminated with infected pigeon feces.