Pathogenicity of two strains of Newcastle disease virus in the grey‐breasted helmet guinea fowl

Abstract

SUMMARYThirty-five 6-week-old guinea fowl keels, seronegative for maternal antibodies to Newcastle disease virus, were infected with Hens strain (33/56) and Kumarov strain of Newcastle disease virus intramucularly (m) or intranasally (IN). Clinical signs were first noticed four days post infection (n) in the group infected al but five days PI in the group infected IN with Hens strain of Newcastle disease virus. These clinical signs were similar in both groups and included anorexia, droopiness, huddling together, greenish diarrhoea and marked cachexia. Prominent nervous signs, including spasms of the head and neck, were observed in groups infected with Hens strain. The major gross lesions observed were emaciation with prominent keel bone, empty intestinal tract and distended gall bladder in most keets. The histological lesions were characterised by meningoencephalitis, necrosis and loss of lymphocytes from splenic and lymphoid aggregates. There was muscular degeneration and necrosis in the gizzard and mild pulmonary congestion and oedema in some keets. Neither gross or microscopic lesions were observed in keels that had received the Kumarov strain.

Low dose velogenic viscerotropic Newcastle disease virus infection caused 30% mortalities in Anak broilers but none in Lohmann Brown layer chickens

“…Wakamatsu et al (2006) studied different strains of vvND virus infection in 4 and 6 weeks old chickens and reported 100% and 92% mortalities respectively. Agoha et al (1992) reported 100% mortality in guinea fowls infected with a chicken strain of NDV. There is no doubt that such low dose infections do occur in nature and most of the time might go unnoticed in areas where vvND is enzootic.…”

Clinical Aspects of Immunosuppression in Poultry

“…Respiratory viruses. Newcastle disease causes lymphocyte necrosis and depletion from lymphoid organs (4,33), and it causes apoptosis of peripheral blood lymphocytes and mononuclear cells (136,138), which may increase susceptibility to secondary bacterial infection.…”

Virus-induced immunosuppression in turkeys (<i>Meleagris gallopavo</i>): A review

“…NDV can damage lymphoid tissues and decrease macrophage secretion and their phagocytosis role. Necrosis of lymphocytes and apoptosis of peripheral blood lymphocytes and mononuclear cells have been also reported (Cheville and Beard, 1972;Agoha et al, 1992;Lam, 1996). aMPV is the causal agent of turkey rhinotracheitis (TRT).…”