Gerloff Nancy A, Khan Salah Uddin, Zanders Natosha, Balish Amanda, Haider Najmul, Islam Ausraful, Chowdhury Sukanta, Rahman Mahmudur Ziaur, Haque Ainul, Hosseini Parviez, Gurley Emily S, Luby Stephen P, Wentworth David E, Donis Ruben O, Sturm-Ramirez Katharine, Davis C Todd
Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America.
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
PLoS One. 2016 Mar 24;11(3):e0152131. doi: 10.1371/journal.pone.0152131. eCollection 2016.
Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year timeframe of sampling, indicate a continuous circulation of these viruses in the country.
对2007年至2013年期间孟加拉国低致病性禽流感（LPAI）A病毒的生态和进化情况进行了评估，评估内容包括流感病毒监测、家禽疫情调查及基因组测序。我们分析了从活禽市场和后院鸡群中采集的506份禽类样本，以鉴定甲型流感病毒。对病毒分离阳性样本（n = 50）进行亚型鉴定，并对其编码完整的基因组进行测序。LPAI分离株中最常鉴定出的亚型为H9N2、H11N3、H4N6和H1N1。较少检测到的亚型包括H1N3、H2N4、H3N2、H3N6、H3N8、H4N2、H5N2、H6N1、H6N7和H7N9。使用系统发育推断方法将基因序列与公开可用序列进行比较。在鉴定出的14种亚型中，大多数病毒基因片段与东南亚、欧洲和/或北非常见的家禽或野生鸟类病毒关系最为密切。LPAI亚型分布在孟加拉国的多个地理位置，表面蛋白和内部蛋白基因片段在系统发育上与多种病毒亚型聚类，表明这些LPAI病毒之间存在广泛的重配。H9N2亚型病毒与其他LPAI亚型不同，因为这些病毒的基因始终聚集在一起，表明该亚型在孟加拉国呈地方流行性。在孟加拉国鉴定出的H9N2毒株在系统发育和抗原性上与先前在孟加拉国检测到的人源H9N2病毒相关，代表了人类感染的潜在来源。相比之下，流行的LPAI H5N2和H7N9病毒在系统发育和抗原性上均与孟加拉国先前在人类中鉴定出的H5病毒以及在中国从人类中分离出的H7N9毒株无关。在孟加拉国，活禽市场销售的家禽携带多种LPAI病毒亚型和高度多样的基因型。这些发现，结合七年的采样时间框架，表明这些病毒在该国持续传播。
