H7N1 avian influenza in Italy (1999 to 2000) in intensively reared chickens and turkeys
H7N1 avian influenza in Italy (1999 to 2000) in intensively reared chickens and turkeys
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DOI：
10.1080/03079450020016779
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发表时间：
2000-12-01
期刊：
影响因子：
2.8
通讯作者：
Alexander, DJ
中科院分区：
文献类型：
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作者：
Capua, I;Mutinelli, F;Alexander, DJ
1999年3月底至12月初，低致病性禽流感（LPAI）流行影响了意大利北部的工业家禽种群。该病毒为H7N1亚型，静脉致病性指数（IVPI）为0.0，推断出低致病性病毒血凝素分子裂解位点编码区域的氨基酸序列。该病毒在易感人群中传播数月后，出现了一种高致病性病毒，其IVPI为3.0，在推断的血凝素分子裂解位点的氨基酸序列中存在多个碱性氨基酸。超过1300万只禽鸟受到该流行病的影响，在本文中，我们报告了对受影响的鸡和火鸡进行的临床、病毒学和组织病理学调查的结果。LPAI引起的临床、肉眼和显微镜下病变在火鸡中比在鸡中更为严重，而高致病性禽流感（HPAI）在两种物种中造成相似的死亡率。目前欧洲立法认为低致病性禽流感和高致病性禽流感是两种完全不同的疾病，不要求对低致病性禽流感实施强制根除政策，但对高致病性禽流感实施强制根除政策。在意大利1999 - 2000年的疫情中，低致病性禽流感在人口密集地区突变为高致病性禽流感，造成了巨大的经济损失。重新考虑目前欧洲联盟关于禽流感的立法，包括H5和H7亚型的低致病性禽流感，可能有助于避免对家禽业造成毁灭性的流行病。
From the end of March to the beginning of December 1999, an epidemic of low pathogenicity avian influenza (LPAI) affected the industrial poultry population of northern Italy. The virus responsible for the epidemic was subtyped as H7N1 with an intravenous pathogenicity index (IVPI) of 0.0, and a deduced amino acid sequence of the region coding for the cleavage site of the haemagglutinin molecule typical of low pathogenicity viruses. The circulation of the virus in a susceptible population for several months caused the emergence of a highly pathogenic virus with an IVPI of 3.0 and the presence of multiple basic amino acids in the deduced amino acid sequence for the cleavage site of the haemagglutinin molecule. Over 13 million birds were affected by the epidemic and, in the present paper, we report the results of the clinical, virological and histopathological investigations performed on affected chickens and turkeys. Clinical, gross and microscopic lesions caused by LPAI were more severe in turkeys than in chickens, while highly pathogenicity avian influenza (HPAI) caused similar mortality rates in both species. Current European legislation considers LPAI and HPAI as two completely distinct diseases, not requiring any compulsory eradication policy for LPAI but enforcing eradication for HPAI. In the Italian 1999 to 2000 epidemic, LPAI mutated to HPAI in a densely populated area, causing great economic losses. A reconsideration of the current European Union legislation on avian influenza, including LPAI of the H5 and H7 subtypes, could possibly be an aid to avoiding devastating epidemics for the poultry industry.