福建省人感染H5N6禽流感病毒与外环境禽流感病毒相关性分析

目的 分析福建省外环境H5亚型禽流感病毒分布情况及与人感染H5N6禽流感的关系,为人感染禽流感的科学防治提供依据。方法 收集2013-2017年福建省外环境常规监测标本信息,进行统计分析。从数据库下载相关禽流感病毒基因序列,进行基因同源性比对和系统进化分析。结果 外环境监测结果统计分析显示:2013-2017年共采集样本4 903份,H5亚型阳性率为4.24%,且不同的网络实验室(χ²=101.033)、监测场所(χ²=45.526)、标本类型(χ²=31.751)和季节(χ²=48.174)阳性率均存在统计学差异(P<0.05)。福建省首例人感染H5N6禽流感(A/Fujian-Sanyuan/21099/2017)病毒全基因序列与6株福建省外环境H5N6病毒的同源性在85.1%~98.5%,与病家院中采集的1株加强监测外环境标本的HA和NA基因同源性分别为100.0%和99.9%。系统进化分析显示:福建省人感染H5N6病毒HA基因与加强监测的外环境H5N6病毒的进化距离最近,与其余6株距离较远,处在不同的进化分枝中,其基因源于H5N8病毒;而NA基因则与7株外环境H5N6病毒的进化距离较近,源于H5N6病毒。结论 福建省冬春季外环境中禽流感活动较为活跃,应加强活禽交易市场的卫生管理工作。福建省发现的首例人感染H5N6禽流感与外环境禽流感病毒的重配可能存在一定的相关性。

Molecular and phylogenitic analysis of avian influenza A (H5N6) between strain isolated from human case and avian influenza viruses of 5 years environmental surveillance,Fujian,China

The aim of this study was to provide the evidence for scientific control of avian influenza by analyzing the external environment avian influenza A (H5) virus and its relationship with human infected avian influenza A (H5N6) in Fujian Province. Surveillance results of environmental avian influenza viruses in Fujian Province from 2013 to 2017 were collected and statistically analyzed. The referenced genetic sequences of avian influenza viruses, downloaded from databases, were analyzed with genetic homology and evolutionary trees. Finally, 4 903 environmental samples were collected. The statistical analysis of surveillance results showed that the ratio of H5 subtype was 4.24%, and there were distinctive differences of positive rate with network laboratories(χ²=101.033), surveillance sites(χ²=45.526), specimen types(χ²=31.751) and seasons(χ²=48.174,P<0.05). The ratio of H5 subtype in Sanming was the highest with 9.83%. Live poultry market, higher than other surveillance sites. Winter and spring were the peak of H5 detection. The gene sequence from 1 strain of human infection with avian influenza A (H5N6) (A/Fujian-Sanyuan/21099/2017) and 7 strains of external environment H5N6 viruses in Fujian were gained, one of which was the strengthened surveillance sample (from the courtyard of the case). The hemagglutinin (HA) gene homology between A/Fujian-Sanyuan/21099/2017 and strengthened surveillance sample was 100.0%, and neuraminidase (NA) was 99.9%. Eight nucleic acid fragments of other external environment samples were 85.1%-98.5%. Phylogenetic analysis showed that the HA from A/Fujian-Sanyuan/21099/2017, originated from H5N8 virus, was closed to virus isolated from strengthened monitored sample and far from the external environmental H5N6 viruses. However, the NA gene was originated from all the external environmental H5N6 viruses, because they were in the same evolutionary branch. In conclusion, the avian influenza was more active in winter and spring in Fujian province, and the health management of live poultry market should be strengthened. The environmental avian influenza might be related with human infection with avian influenza A (H5N6), which was the first case in Fujian.