Detection and analysis of low pathogenic avian influenza in poultry in eastern china from 2002 to 2009 | 2002―2009年中国华东地区家禽低致病性禽流感的病原学检测与分析

Chinese. 【目的】为确定中国华东地区家禽中禽低致病性禽流感(Low pathogenic avian influenza, LPAI)的流行和分布状况。【方法】 2002年7月至2009年9月在江苏省扬州市活禽市场 (live poultry markets, LPMs)采集来自不同省份的家禽泄殖腔拭子11 645个,用鸡胚尿囊腔传代接种法分离病毒,进行了长达8年的LPAI的病毒学监测。【结果】禽流感阳性样品1 158个,总分离率9.94%。所分离到的亚型及各亚型分离率从高到低依次为H3、H6、H11、H1、H4、H9、H10、H8。【结论】禽流感的分布季节性非常明显,以冬、春为高,各亚型又有其不同分布特点。到目前为止,已经从家鸭中分离到8种HA亚型,依次为H1、H3、H4、H6、H8、H9、H10、H11;7种NA亚型,包括N1、N2、N3、N4、N5、N6、N8,两者之间有17种组合,与野鸭的带毒情况十分相似。家鸭还很容易发生混合感染,2007年以来以H6亚型为主,H3、H11、H4、H9等很多亚型都可与其混合感染,这为禽流感病毒(avian influenza viruses, AIVs)基因重组产生新的亚型及毒力的变异提供了很好的载体。

English. 【Objective】 This study engaged in epidemiological surveillance of low pathogenic avian influenza A viruses in poultry in Eastern China. 【Method】 From July 2002 to September 2009, 11 645 cloacal swab samples were collected from poultry in the LPMs (liveCpoultry markets), which were from different provinces. All cloacal swabs were tested for hemagglutinating viruses by inoculating embryonated hens eggs. 【Result】 There were 1 158 strains of AIVs were isolated with an isolation rate of 9.94%. These strains of AIV belonged to eight HA subtypes, the isolation rate of high to low were H3, H6, H11, H1, H4, H9, H10, and H8. 【Conclusion】The isolation rate of AIVs was distributed with significant seasonal variations, higher in winter and spring and lower in summer. The distribution of HA subtypes of AIVs was also uneven in different months. So far, eight HA subtypes (H1, H3, H4, H6, H8, H9, H10 and H11) and seven NA subtypes (N1, N2, N3, N4 , N5, N6 and N8) were isolated from domestic ducks. Strains in HA and NA subtypes combination included the following 17 subtypes. Domestic duck is still the most prone to mixed infections, and since 2007 H6 subtypes have played an important role that are able to mix infect poultry with H3, H11, H4, H9 subtype etc, providing a good vector to generate new subtypes and variation of virulence.