作 者：
冯肖肖;赵灵燕;刘霞;黄靖;张璐;董建斐;陈伟良;徐辉
摘 要：
为评估高致病性禽流感(HPAI)疫病风险和免疫水平情况,2021年3-5月在浙江省11个地市采集血清、家禽拭子和环境样本4123份,采用血凝抑制试验和荧光RT-PCR方法,检测和分析家禽HPAI强制免疫抗体水平和感染情况.结果显示:H5亚型(Re11)AIV免疫抗体样本合格率为91.70%,场点合格率为90.00%;H5亚型(Re12)AIV免疫抗体样本合格率为90.42%,场点合格率为92.50%;H7N9亚型(Re3)AIV免疫抗体样本合格率为91.30%,场点合格率为90.00%;家禽总体免疫抗体合格率均在90%以上.不同地区H5亚型(Re11)AIV免疫抗体样本合格率为85.00%~99.17%;H5亚型(Re12)AIV免疫抗体样本合格率为82.71%~94.38%;H7N9亚型(Re3)AIV免疫抗体样本合格率为70.79%~99.17%.不同场点AIV免疫抗体样本合格率为84.49%~97.00%,屠宰场和散养户的AIV免疫抗体样本合格率低于种禽场和规模场.鸡和鸭AIV免疫抗体样本合格率分别在92%和86%以上,鸡的免疫效果要优于鸭.全省未检出H5亚型和H7亚型HPAIV核酸阳性,但监测到其他亚型的低致病性禽流感病毒(LPAIV)的存在.对监测到的AIV阳性样本采用荧光RT-PCR方法进一步分析,103份A型流感样品中发现存在H2(22.33%)、H9(17.48%)、H10(15.53%)、H3(5.83%)和H6(1.94%)5种HA亚型,N3(57.28%)、N8(42.72%)、N2(9.71%)、N6(7.77%)、N9(2.91%)和N1(1.94%)6种NA亚型.103份样品来自12个场点,分别有33.33%和58.33%的场点(屠宰场和市场)检出2种以上HA和NA亚型.家禽流通和屠宰环节中存在不同亚型LPAIV混合感染情况.监测结果表明,HPAI防控措施效果良好,浙江省部分地区免疫效果稍低,但家禽免疫抗体总体水平达到农业农村部要求(70%)以上;浙江省未发现有HPAIV核酸阳性,HPAI疫情发生风险较低,但家禽和环境中存在多亚型LPAIV感染的现象.
译 名：
Special Surveillance and Assessment of Avian Influenza in Zhejiang Province in 2021
作 者：
FENG Xiaoxiao;ZHAO Lingyan;LIU Xia;HUANG Jing;ZHANG Lu;DONG Jianfei;CHEN Weiliang;XU Hui;Zhejiang Animal Disease Prevention and Control Center;
关键词：
HPAI;;surveillance;;immune antibody;;genotyping
摘 要：
In order to investigate the situation of avian influenza immune antibody and virus infection in Zhejiang province, HI and fluorescent RT-PCR test methods were used to carry out special monitoring of avian influenza in Zhejiang province to detect the immune antibody and virus nucleic acid. The qualified rate of H5 subtype(Re11 and Re12) avian influenza real antibody was 91.70% and 90.42%respectively, and the qualified rate of H7N9 subtype avian infl uenza real antibody was 91.30%. The qualified rates of immune antibodies against H5 subtype(Re11 and Re12) and H7N9 subtype of avian influenza in different regions were 85.00%-99.17%, 82.71%-94.38%and 70.79%-99.17%, respectively. The test results of different sites showed that the qualified rates of antibody from different sites were between 84.49%-97.00%, and the qualified rate of antibody in slaughterhouse and scattering raising-households samples was lower than that in breeding farms and commercial farms. The qualified rates of H5 and H7N9 subtype antibody from chicken and duck were above 92% and 86% respectively. No nucleic acid of H5 and H7 subtypes of Avian influenza virus was detected. A total of 103 samples of Low pathogenic avian influenza virus were detected, and the positive rate was 4.34%. Five HA subtypes were detected in LPAIV samples, including H2(22.33%), H9(17.48%), H10(15.53%), H3(5.83%) and H6(1.94%). Six NA subtypes of N3(57.28%), N8(42.72%), N2(9.71%), N6(7.77%), N9(2.91%) and N1(1.94%) were also detected. And different HA and NA subtypes were detected in slaughterhouses and live poultry markets. The results showed that the overall prevention and control effect of highly pathogenic avian influenza(HPAI) in Zhejiang Province was good, and the immune antibody level was above the national minimum standard(70%). No HPAI virus infection was found, however, there were a few cases of low pathogenic avian influenza(LPAI) infection.
