LaSota vaccination may not protect against the lesions of velogenic newcastle disease in chickens
LaSota vaccination may not protect against the lesions of velogenic newcastle disease in chickens
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拉索塔疫苗接种可能无法预防鸡的烈性新城疫病变
DOI：
10.1007/s11250-008-9210-x
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发表时间：
2009
影响因子：
1.7
通讯作者：
J. A. Nwanta
中科院分区：
文献类型：
--
作者：
W. Ezema;J. Okoye;J. A. Nwanta
用VGF-1肌内接种两组六周龄公鸡，包括40只免疫的和40只未免疫的鸟，VGF-1是尼日利亚的一种地方性强毒纽卡斯尔病病毒（VNDV）株。除了在接种后第5天和第20天（PI）体重的显著损失（p < 0.05）之外，免疫的鸟未显示任何临床体征。但未免疫的鸟从PI第2天显示出以厌食和嗜睡为特征的疾病临床体征。在PI第3天，随后出现抑郁、腹泻、角弓反张、体重减轻（p < 0.05）和高死亡率（96.9%）。免疫组和非免疫组的法氏囊、脾脏和胸腺均出现严重萎缩。这些淋巴器官的组织学切片显示淋巴细胞坏死和耗竭。肉眼和显微镜下病变均在未免疫鸡中更严重。在未免疫鸡的法氏囊滤泡中观察到明显的气球样变性。这种病变以前没有被描述为任何其他疾病，可以诊断为VND。结果还表明，VND可引起免疫鸡淋巴器官的明显萎缩，这可能导致免疫抑制，但不具有纽卡斯尔病（ND）的特征性体征。这无疑强调了疫苗接种作为家禽业生物安全措施的局限性。
Two groups of six weeks old cockerels comprising 40 immunized and 40 non-immunized birds were inoculated intramuscularly with VGF-1, which is a local Nigerian strain of velogenic Newcastle disease virus (VNDV). Immunized birds did not show any clinical signs except significant loss (p < 0.05) in body weight on days 5 and 20 post inoculation (PI). But the non-immunized birds showed clinical signs of disease characterized by anorexia and drowsiness from day 2 PI. These were followed on day 3 PI by depression, diarrhoea, opisthotonus, weight loss (p < 0.05) and high mortalities (96.9%). Both the immunized and non-immunized groups showed severe atrophy of the bursa, spleen and thymus. Histopathological section of these lymphoid organs showed necrosis and depletion of lymphocytes. Both the gross and microscopic lesions were more severe in the non-immunized birds. Marked ballooning degeneration was observed in the bursal follicles of the non-immunized birds. This lesion has not been described earlier for any other disease and could be diagnostic for VND. Our results also showed that VND can cause marked atrophy of the lymphoid organs, which may lead to immunosupression without the characteristic signs of Newcastle disease (ND) in vaccinated chickens. This no doubt emphasizes the limitation of vaccination as a biosecurity measure in poultry industry.