自主活动鸟类禽流感及新城疫的生态学与流行病学调查分析

在2004年初H5亚型禽流感在中国内地引起暴发前后，于湖北、广西二疫区市县的生态系中，自健康的鹰、鸽子、野鸭和鹌鹑中采集了54份血清，应用血凝抑制试验（HI）对其进行了血清学检测，并将获得的血清学检测数据进行了统计学分析。分析结果显示，在总共采集的54份血清样品中，抗新城疫病毒（NDV）抗体、抗It6亚型禽流感病毒（H6）抗体、抗H9亚型禽流感病毒（H9）抗体、抗H5亚型禽流感病毒（H5）抗体阳性率分别为64．8％、64．8％、75．9％、29．6％。推断这一时期新城疫病毒（NDV）、H6亚型禽流感病毒（H6）、H9亚型禽流感病毒（H9）和H5亚型禽流感病毒（H5）共循环于该生态系中，其中新城疫病毒、H9、H6亚型禽流感病毒长期、稳定循环于该生态系中，为该生态系主要流行血清型。血凝抑制试验检测结果发现，抗H5亚型禽流感病毒抗体效价较低，最高仅为640，其阳性率为29．6％，推断其可能为新近传入的病毒或新近重组变异出现的新病毒、与该次流感暴发相关的新病毒，这一推断还有待于通过对病毒基因序列的分析而做进一步验证：另外，新城疫病毒在该生态系中的稳定循环，构成了对家禽持久、潜在的威胁。对于自1994年以来，长期稳定循环于我国生态系及家禽中的H9亚型禽流感病毒则仍然是以G9-like为优势亚组。本研究结果还提示我们，对我国自主活动鸟类的生态系中抗禽流感病毒抗体的监测是预警、预报我国家禽流感暴发的有效途径，也是十分必要的，同时，血清学的检测结果为我们进一步的分子水平的分析研究提供了明确的靶向。

Epidemiology surveillance and analysis on avian influenza and newcastle disease of free-living birds in Guangxi and Hubei province of China in 2004

Hemagglutinin-Inhibition test is used in this study to monitor the 54 serum samples from healthy hawks, pigeons and quails in the ecosystem in Hubei and Guangxi province, where had outbreaks of H5 subtype HPA1 in 2004. Furthermore, the data are analyzed statistically. The results show that the positive rates of antibody anti Newcastle disease virus, H9 subtype AIV, H6 subtype AIV and H5 subtype AIV respectively is 64.8 %, 64.8 %, 75.9 %, 29.6 %. According to this, we got the conclusion that NDV, H9 subtype AIV, H6 subtype AIV and H5 subtype AIV co-circle around this ecosystem, And NDV, H9 subtype AIV and H6 subtype AIV circled stably and chronically in this ecosystem and are the leading prevalent serotype. On the other hand, the positive rate of antibody anti H5 subtype AIV is 29.6 %, the highest titer of antibody of that is 640. It is impossible that the H5 subtype AIV is newly transmitted into the ecosystem or a mew recombinant. And it is correlative to the outbreaks at this time there. Of course, that should be validated more at molecular level. In this study, G9-like AIV has been the leading prevalent subtype AIV and circled stably and chronically in most area of China since 1994. Therefore, it is an effective and necessary approach for forecast of AIV of poultry to monitor antibody anti AIV of serum of free-living birds in China. At the same time, the results of this study should be as a base to analyze and research at molecular level.