禽源冠状病毒监测简报

Overview on the Surveillance of Avian-orgin Coronaviruses

冠状病毒(Coronaviruses)在分类地位上属于套式病毒目(Nidovirales)冠状病毒科(Coronaviridae)正冠状病毒亚科(Orthocoronavirinae),包括α、β、γ和δ等4个属,可感染包括人类在内的多种动物。其中,α冠状病毒属主要感染人和猪、犬、猫、蝙蝠等,β冠状病毒属主要感染人和牛、马、猪、鼠、蝙蝠等哺乳动物,γ冠状病毒属主要感染鸡、火鸡、鸭、鹅等禽类,δ冠状病毒属主要感染野禽和猪。引起此次新型冠状病毒肺炎疫情的病毒(2019-nCoV)属于冠状病毒科β冠状病毒属。可感染禽类的冠状病毒主要来自γ冠状病毒属和δ冠状病毒属。鸡传染性支气管炎病毒(IBV)等家禽中分离到的冠状病毒均为γ冠状病毒属。家禽冠状病毒感染危害较大的是IBV。此外,鸭冠状病毒、鹅冠状病毒和鸽冠状病毒等在家禽中也有检出。一些野禽可感染δ属冠状病毒(如鹅口疮冠状病毒HKU12等)。2013年以来,中国动物卫生与流行病学中心对全国17省份共计5 249份家禽样品进行了禽源冠状病毒检测,共检测到IBV 446株,新型鸭冠状病毒和新型鸽冠状病毒等新型禽冠状病毒共277株,IBV、新型鸭冠状病毒、新型鸽冠状病毒的检出率分别为8.50%、2.04%、3.24%。对2019-nCoV与禽源冠状病毒的亲缘关系进行分析发现,2019-nCoV与已知的禽源冠状病毒核苷酸同源性较低;基于冠状病毒1ab基因保守区域的进化分析表明,2019-nCoV与禽源冠状病毒亲缘关系较远。基于上述分析,初步排除2019-nCoV来源于已知家禽冠状病毒的可能性。

Coronaviruses belong to Nidovirales,family Coronaviridae,Orthocoronavirinae,which are divided into four genera:Alphacoronavirus,Betacoronavirus,Gammacoronavirus and Deltacoronavirus,and can infect many animals including humans. Among them,Alphacoronavirus mainly infects humans and pigs,dogs,cats,bats,etc.,Betacoronavirus mainly infects humans,cattle,horses,pigs,mice,bats and other mammals,and Gammacoronavirus mainly infects chickens,turkeys,ducks,geese and other birds,Deltacoronavirus mainly infects wild birds and pigs. The emerging 2019-nCoV causing novel coronavirus pneumonia(NCP)outbreak in China belongs to the Betacoronavirus of Coronaviridae. Coronaviruses that can infect birds are mainly from the Gammacoronavirus and Deltacoronavirus of Coronaviridae. Coronaviruses isolated from poultry such as avian infectious bronchitis virus(IBV)are all Gammacoronavirus. In the avian coronaviruses,IBV is more harmful to the poultry. In addition,duck coronavirus,goose coronavirus and pigeon coronavirus were also detected. Some wild birds can be infected with Deltacoronavirus(such as thrush coronavirus HKU12,etc.). Since 2013,a total of 5 249 poultry samples from 17 provinces in China have been detected by China Animal Health and Epidemiology Center,a total of 446 avian infectious bronchitis viruses,277 of novel duck coronaviruses and novel pigeon coronaviruses have been detected. The positive rates of avian infectious bronchitis virus,novel duck coronavirus,and novel pigeon coronavirus were 8.50%,2.04% and 3.24%,respectively.Analysis of the relationship between 2019-nCoV and avian coronavirus found that the nucleotide homology between 2019-nCoV and known avian-orgin coronaviruses was quite lower compared with mammal-origin coronaviruses. Evolutionary analysis based on the conserved region of the coronavirus 1 ab gene shows that 2019-nCoV is far from avian coronavirus. According to the above analysis results,the possibility of 2019-nCoV originating from the known avian-origin coronaviruses can be preliminarily ruled out.