Islam Ariful, Amin Emama, Khan Md Arif, Islam Monjurul, Gupta Suman Das, Abedin Josefina, Rahman Mohammed Ziaur, Forwood Jade K, Hosaain Mohammed Enayet, Shirin Tahmina
Biosecurity Research Program and Training Centre, Gulbali Institute, Charles Sturt University, Wagga Wagga, Australia.
Training Hub Promoting Regional Industry and Innovation in Virology and Epidemiology, Gulbali Institute, Charles Sturt University, Wagga Wagga, Australia.
Emerg Microbes Infect. 2025 Dec;14(1):2498574. doi: 10.1080/22221751.2025.2498574. Epub 2025 May 29.
Low pathogenicity avian influenza (LPAI) H9N2 has been enzootic in Bangladeshi poultry since 2006. H9N2 outbreaks can decrease egg production and growth and pose a risk to human health. The role of avian hosts in the persistence, evolution, and dispersion of H9N2 is poorly understood in Bangladesh. Hence, this study unveils the intricate role of major host species in virus maintenance and evolution and the temporal and seasonal patterns of H9N2 in Bangladesh from 2006 to 2023. Multinomial logistic regression analysis indicated that the circulation of H9N2 in different species and interfaces is significantly influenced by the seasons. Bayesian phylogenetic analysis of H9N2 sequences in Bangladesh revealed two distinct lineages: G1 and Eurasian. The G1 lineage split into two clusters, coexisting until 2019, at which point only one cluster persisted. Bayesian phylodynamic analysis of G1 lineage unveiled frequent bidirectional viral transitions among ducks, chickens, and quails. Chickens might be a pivotal source of H9N2 in Bangladesh, with a higher number of viral transitions from chickens to ducks and quails. Quails appear to acquire most of their viral transitions from chickens rather than ducks, suggesting that quail epizootics are primarily triggered by spillover events from chickens. Our results suggest viral circulation in commercial chickens despite vaccination. The vaccination approach should be revised, assess vaccine efficacy, and extension of vaccination to backyard chickens and quails.
自2006年以来，低致病性禽流感（LPAI）H9N2在孟加拉国的家禽中呈地方性流行。H9N2疫情会降低产蛋量和生长速度，并对人类健康构成风险。在孟加拉国，禽类宿主在H9N2的持续存在、进化和传播中所起的作用尚不清楚。因此，本研究揭示了主要宿主物种在病毒维持和进化中的复杂作用，以及2006年至2023年期间孟加拉国H9N2的时间和季节模式。多项逻辑回归分析表明，H9N2在不同物种和界面中的传播受季节的显著影响。对孟加拉国H9N2序列的贝叶斯系统发育分析揭示了两个不同的谱系：G1和欧亚谱系。G1谱系分为两个簇，直到2019年共存，此后只有一个簇持续存在。对G1谱系的贝叶斯系统动力学分析揭示了鸭、鸡和鹌鹑之间频繁的双向病毒转移。鸡可能是孟加拉国H9N2的一个关键来源，从鸡到鸭和鹌鹑的病毒转移数量更多。鹌鹑似乎大部分病毒转移是从鸡而不是鸭那里获得的，这表明鹌鹑疫情主要是由鸡的溢出事件引发的。我们的结果表明，尽管进行了疫苗接种，商业鸡中仍存在病毒传播。应修订疫苗接种方法，评估疫苗效力，并将疫苗接种扩展到后院鸡和鹌鹑。
