2017年潍坊市对首例H7N9禽流感疫情应急监测结果分析

Analysis of emergency surveillance results of epidemic situation of H7N9 in Weifang in 2017

目的 2017年4月潍坊市确诊首例人感染高致病性禽流感H7N9病例后,通过对密切接触者带毒情况调查及大范围活禽市场禽流感病毒开展监测工作,为疫情防控提供可靠实验依据。方法实时荧光定量PCR(RT-PCR)法对密切接触者咽拭子标本及活禽市场环境标本进行禽流感病毒的核酸检测。结果 103例密切接触者中,3例为H3亚型季节性流感病毒携带者,未发现H7N9病毒携带者。508份环境标本中,A型核酸阳性率为24.4%,其中H7亚型阳性率为10.2%,明显高于H5亚型(0.2%)、H9亚型(5.5%)及H7和H9亚型双阳性(3.0%);各类型标本中,宰杀或摆放禽类案板表面擦拭标本(14.0%)和清洗禽类污水等标本中,H7亚型检出率高于与其他类型标本中的阳性率,差异有统计学意义(χ2=8.67,P<0.05)。结论潍坊市活禽市场H7亚型禽流感病毒污染情况较普遍,提示人感染H7N9风险较高,因此需采取强有力措施以控制疫情进一步扩散。

Objective To provide reliable laboratory data for controlling the epidemic situation by investigating the close contacts carrying the virus and monitoring the epidemic of this virus in live poultry markets after the first H7 N9 case was confirmed in Weifang in April,2017. Methods Environmental and the close contact samples were detected by real-time PCR for avian influenza virus nucleic acid. Results Of the 103 close contacts,3 were H3 subtype seasonal influenza carriers and no H7 N9 virus carriers were found. Among the 508 environmental samples,the positive rate of type A nucleic acid was 24. 4%,of which the positive rate of H7 subtype was 10. 2%,which was significantly higher than that of H5 subtype（ 0. 2%）,H9 subtype（ 5. 5%）,and H7 and H9 subtypes with double positivity（ 3. 0%）; in all types of specimens,the detection rate of H7 subtype in the samples of chopping board for slaughtered or placed poultry（ 14. 0%） and in the samples of poultry cleaning wastewater,the detection rate of H7 subtype is higher than that of the other types of specimens,with the differences statistically significant（ χ2= 8. 67,P〈0. 05）. Conclusion The infection of H7 subtype avian flu virus in the live poultry market in Weifang is relatively common,suggesting that the risk of human infection with H7 N9 is high. Therefore,it is necessary to take strong measures to control the spread of the epidemic.