Review of Newcastle Disease in Cormorants

Abstract

-Pathogenic Newcastle disease virus (NDV) caused wide-spread mortality of Double-crested Cormorants (Phalacrocorax auritus) in Canada in 1990 and in Canada and the USA in 1992. Presence of pathogenic NDV in Double-crested Cormorants is important because of the potential risk of spread to other wild birds and domestic poultry, and the effect on population dynamics of Double-crested Cormorants. The first isolation of NDV from a member of the Phalacrocoracidae was from European Shags (P aristotelis) in Scotland in 1949. It was found in Great Cormorants (P carbo) from the Volga Delta in 1974, and in Double-crested Cormorants from Quebec in 1975. From 1990 to 1997, pathogenic NDV was isolated from Double-crested Cormorants in different parts of North America in five of eight years. Newcastle disease may cause high mortality of juvenile Double-crested Cormorants; affected birds typically have wing or leg paralysis, loss of balance, and non-suppurative inflammation of brain and spinal cord. There are no reports of extensive mortality from Newcastle disease in wild birds cohabiting with Double-crested Cormorants; however, it is likely that commercial range turkeys contracted Newcastle disease from Double-Crested Cormorants in North Dakota in 1992. Newcastle disease virus isolates from Double-crested Cormorants from widely separated breeding sites and from different years have the same predicted amino acid sequence of the fusion protein cleavage site. This sequence includes the substitution of arginine for glutamine at position 110 of the fusion protein, which appears to be unique for NDV isolates obtained from cormorants and associated species since 1990. Received 19 March 1999, accepted 24July 1999.