Šolaja Sofija, Glišić Dimitrije, Veljović Ljubiša, Milošević Ivan, Nićković Emilija, Nišavić Jakov, Milićević Vesna
Department of Virology, Institute of Veterinary Medicine of Serbia, Janisa Janulisa 14, 11000 Belgrade, Serbia.
Department of Histology and Embryology, Faculty of Veterinary Medicine, University of Belgrade, Bulevar Oslobođenja 18, 11000 Belgrade, Serbia.
Pathogens. 2025 Jun 25;14(7):636. doi: 10.3390/pathogens14070636.
Highly pathogenic avian influenza (HPAI) H5N1 continues to pose a major threat to animal and public health. Since its emergence, clade 2.3.4.4b has become the dominant global lineage, associated with widespread outbreaks in Europe. This study aimed to characterise the H5N1 strains detected in backyard chickens in Serbia and investigate their phylogenetic and phylogeographic relationships with historical and currently circulating strains in Serbia and the broader region. Samples collected in 2024 were tested by qRT-PCR, and positive samples were propagated in MDCK cells. Whole genome sequencing of isolated virus was performed using the MinION Mk1C platform (ONT, Oxford, UK). Bayesian phylogenetic and phylogeographic analyses were conducted using BEAST X and SPREAD3 v.9.6. The results revealed three independent introductions of H5N1 into Serbia between 2020 and 2024. The spatiotemporal diffusion patterns confirmed both north-south and west-east viral spread from Northern and Central Europe into the Balkans. Additionally, Serbia was identified as a critical transit and divergence point in the regional transmission network, highlighting its role in the spread of H5N1 between Western and Eastern Europe. These findings underscore the importance of continued genomic surveillance in both domestic and wild bird populations to better understand and reduce HPAI spread.
高致病性禽流感（HPAI）H5N1继续对动物和公共卫生构成重大威胁。自出现以来，2.3.4.4b分支已成为全球主要谱系，与欧洲的广泛疫情有关。本研究旨在对在塞尔维亚后院鸡中检测到的H5N1毒株进行特征分析，并调查它们与塞尔维亚及更广泛地区的历史和当前流行毒株之间的系统发育和系统地理学关系。对2024年采集的样本进行qRT-PCR检测，阳性样本在MDCK细胞中传代培养。使用MinION Mk1C平台（英国牛津纳米孔技术公司）对分离出的病毒进行全基因组测序。使用BEAST X和SPREAD3 v.9.6进行贝叶斯系统发育和系统地理学分析。结果显示，2020年至2024年期间，H5N1毒株三次独立传入塞尔维亚。时空扩散模式证实了病毒从北欧和中欧向巴尔干地区的南北和东西方向传播。此外，塞尔维亚被确定为区域传播网络中的关键过境点和分歧点，凸显了其在H5N1在西欧和东欧传播中的作用。这些发现强调了对家禽和野生鸟类种群持续进行基因组监测对于更好地了解和减少高致病性禽流感传播的重要性。
