Adlhoch Cornelia, Fusaro Alice, Gonzales José L, Kuiken Thijs, Marangon Stefano, Niqueux Éric, Staubach Christoph, Terregino Calogero, Muñoz Guajardo Irene, Lima Eliana, Baldinelli Francesca
EFSA J. 2021 Mar 3;19(3):e06497. doi: 10.2903/j.efsa.2021.6497. eCollection 2021 Mar.
Between 8 December 2020 and 23 February 2021, 1,022 highly pathogenic avian influenza (HPAI) virus detectionswere reported in 25 EU/EEA countries and the UK in poultry (n=592), wild (n=421) and captive birds (n=9).The majority of the detections were reported by Francethat accounted for 442 outbreaks in poultry,mostly located inthe Landes regionandaffecting the foie gras production industry,and six wild bird detections; Germany,who reported 207 detections in wild birds and 50 poultry outbreaks; Denmark,with 63 detections in wild birds and one poultry outbreak; and Poland,with 37 poultry outbreaks and 24 wild bird detections. Due to the continued presence of HPAI A(H5) viruses in wild birds and the environment,there is still a risk of avian influenza incursions with the potential further spread between establishments, primarily in areas with high poultry densities. As the currently circulating HPAI A(H5N8) virus cancause high mortality also in affected duck farms, mortality eventscan be seen as a good indicator of virus presence. However,also subclinical virusspread in this type of poultry production system have been reported.To improve early detection of infection in poultry within the surveillance zone, the clinical inspection of duck establishments should be complemented by encouraging farmers to collect dead birds to be pooled and tested weekly (bucket sampling).Six different genotypes were identified to date in Europe and Russia, suggesting a high propensity of these viruses to undergo multiple reassortment events. To date, no evidence of fixation of known mutations previously described as associated to zoonotic potential has been observed in HPAI viruses currently circulanting in Europe based on the available sequences.Seven cases due to A(H5N8) HPAI virus have been reported from Russia, all were poultry workerswith mild or no symptoms. Five human cases due to A(H5N6) HPAI and 10 cases due to A(H9N2) LPAI viruseshave been reported from China. The risk for the general population as well as travel-related imported human cases is assessed as very lowand the risk forpeople occupationally exposedpeople as low.Any human infections with avian influenza viruses are notifiablewithin 24 hoursthrough the Early Warning and Response System (EWRS) and the International Health Regulations (IHR) notification system.
2020年12月8日至2021年2月23日期间，欧盟/欧洲经济区25个国家及英国报告了1022起高致病性禽流感（HPAI）病毒检测事件，涉及家禽（n = 592）、野生鸟类（n = 421）和圈养鸟类（n = 9）。大部分检测事件由法国报告，该国报告了442起家禽疫情，主要集中在朗德地区，影响了肥肝生产行业，还报告了6起野生鸟类检测事件；德国报告了207起野生鸟类检测事件和50起家禽疫情；丹麦报告了63起野生鸟类检测事件和1起家禽疫情；波兰报告了37起家禽疫情和24起野生鸟类检测事件。由于野生鸟类和环境中持续存在HPAI A（H5）病毒，禽流感仍有传入风险，且可能在养殖场之间进一步传播，主要发生在家禽密度高的地区。由于目前传播的HPAI A（H5N8）病毒在受影响的鸭场也可导致高死亡率，死亡事件可被视为病毒存在的良好指标。然而，也有报告称这种家禽生产系统中存在亚临床病毒传播。为了在监测区内改善对家禽感染的早期检测，除了对鸭场进行临床检查外，还应鼓励养殖户每周收集死禽进行集中检测（桶式采样）。欧洲和俄罗斯迄今已鉴定出六种不同的基因型，这表明这些病毒极易发生多次重配事件。根据现有序列，目前在欧洲传播的HPAI病毒中，尚未观察到先前描述的与人畜共患病潜力相关的已知突变固定的证据。俄罗斯报告了7起因A（H5N8）HPAI病毒导致的病例，所有病例均为家禽工人，症状轻微或无症状。中国报告了5起因A（H5N6）HPAI病毒导致的人间病例和10起因A（H9N2）低致病性禽流感病毒导致的病例。一般人群以及与旅行相关的输入性人间病例的风险评估为极低，职业暴露人群的风险评估为低。任何人感染禽流感病毒都应通过早期预警与应对系统（EWRS）和国际卫生条例（IHR）通报系统在24小时内通报。
