Gowthaman Vasudevan, Singh Shambu Dayal, Dhama Kuldeep, Srinivasan Palani, Saravanan Sellappan, Murthy Thippichettypalayam Ramasamy Gopala Krishna, Sukumar Kuppanan, Mathapati Basavaraj, Lebarbenchon Camille, Malik Yashpal Singh, Ramakrishnan Muthannan Andavar
Avian Diseases Section, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243 122 India ; Poultry Disease Diagnosis and Surveillance Laboratory, Veterinary College and Research Institute Campus, Tamil Nadu Veterinary and Animal Sciences University, Namakkal, Tamil Nadu 637 002 India.
Avian Diseases Section, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243 122 India.
Virusdisease. 2016 Dec;27(4):382-386. doi: 10.1007/s13337-016-0350-8. Epub 2016 Oct 5.
Avian influenza is a highly infectious and dynamically evolving disease of birds causing high morbidity and mortality. It is caused by avian influenza virus (AIV) that belongs to the family Orthomyxoviridae. Two types of AIV have been described based on their pathogenicity viz. highly pathogenic avian influenza virus that causes severe disease with high mortality and low pathogenic avian influenza virus (LPAI) that generally causes asymptomatic infection or a mild disease. The H9N2 subtype is the widely circulated LPAI type in the world. The H9N2 subtype of was first reported from northern India in March 2003. However, systematical surveillance information for the evolution of H9N2 viruses in poultry flocks of Southern India is lacking. The present study reports the isolation and characterization of H9N2 isolates from the southern parts of the country during the period between May 2010 and September 2011. Out of the 30 poultry flocks investigated, six were found to be positive for HA activity. Further, all the six samples conformed as AIV. Partial nucleotide sequencing of the HA and NA genes revealed that all were belonging to the H9N2 subtype. Phylogenetically, the HA and NA genes of the H9N2 viruses from India clustered with those isolated from Bangladesh, Pakistan and the Middle East, although we were not able to conclude on their exact geographic origin.
禽流感是一种极具传染性且不断动态演变的禽类疾病，可导致高发病率和高死亡率。它由属于正粘病毒科的禽流感病毒（AIV）引起。根据致病性，已描述了两种类型的AIV，即高致病性禽流感病毒，可导致严重疾病和高死亡率；以及低致病性禽流感病毒（LPAI），通常引起无症状感染或轻度疾病。H9N2亚型是世界上广泛传播的低致病性禽流感病毒类型。H9N2亚型于2003年3月首次在印度北部被报道。然而，印度南部家禽群中H9N2病毒进化的系统监测信息尚缺。本研究报告了2010年5月至2011年9月期间从该国南部分离和鉴定的H9N2分离株。在调查的30个家禽群中，有6个被发现血凝素（HA）活性呈阳性。此外，所有6个样本均确认为禽流感病毒。HA和神经氨酸酶（NA）基因的部分核苷酸测序显示，所有样本均属于H9N2亚型。从系统发育来看，来自印度的H9N2病毒的HA和NA基因与从孟加拉国、巴基斯坦和中东分离的病毒聚集在一起，尽管我们无法确定它们的确切地理来源。
