Genesis and Spread of Newly Emerged Highly Pathogenic H7N9 Avian Viruses in Mainland China
| Autor: | Zhenli Liang, Yuelong Shu, Zi Li, Wenfei Zhu, Jia Liu, Xiaoxu Zeng, Yiwei Huang, Wenbing Chen, Hong Bo, Lei Yang, Jie Wu, Weixian Shi, Shun-Xiang Qi, Minmei Chen, Dayan Wang, Xiang Zhao, Ye Zhang, Xiyan Li, Jie Dong, Weijuan Huang, Pengbo Yu, Wei Shi, Tao Chen |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Delta Mainland China China Genotype viruses Highly pathogenic Immunology Hemagglutinin (influenza) Hemagglutinin Glycoproteins Influenza Virus Influenza A Virus H7N9 Subtype medicine.disease_cause Microbiology Poultry Virus Disease Outbreaks Birds Evolution Molecular 03 medical and health sciences Virology Influenza Human medicine Animals Humans Phylogeny biology virus diseases Outbreak Influenza A virus subtype H5N1 030104 developmental biology Genetic Diversity and Evolution Influenza in Birds Insect Science Mutation biology.protein Reassortant Viruses |
| Zdroj: | Journal of Virology. 91 |
| ISSN: | 1098-5514 0022-538X |
| DOI: | 10.1128/jvi.01277-17 |
| Popis: | The novel low-pathogenic avian influenza A H7N9 viruses (LPAI H7N9 viruses) have been a threat to public health since their emergence in 2013 because of the high rates of mortality and morbidity that they cause. Recently, highly pathogenic variants of these avian influenza A H7N9 viruses (HPAI H7N9 viruses) have emerged and caused human infections and outbreaks among poultry in mainland China. However, it is still unclear how the HPAI H7N9 virus was generated and how it evolved and spread in China. Here, we show that the ancestor virus of the HPAI H7N9 viruses originated in the Yangtze River Delta region and spread southward to the Pearl River Delta region, possibly through live poultry trade. After introduction into the Pearl River Delta region, the origin LPAI H7N9 virus acquired four amino acid insertions in the hemagglutinin (HA) protein cleavage site and mutated into the HPAI H7N9 virus in late May 2016. Afterward, the HPAI H7N9 viruses further reassorted with LPAI H7N9 or H9N2 viruses locally and generated multiple different genotypes. As of 14 July 2017, the HPAI H7N9 viruses had spread from Guangdong Province to at least 12 other provinces. The rapid geographical expansion and genetic evolution of the HPAI H7N9 viruses pose a great challenge not only to public health but also to poultry production. Effective control measures, including enhanced surveillance, are therefore urgently needed. IMPORTANCE The LPAI H7N9 virus has caused five outbreak waves in humans and was recently reported to have mutated into highly pathogenic variants. It is unknown how the HPAI H7N9 virus originated, evolved, and disseminated in China. In this study, we comprehensively analyzed the sequences of HPAI H7N9 viruses from 28 human and 21 environmental samples covering eight provinces in China that were taken from November 2016 to June 2017. The results show that the ancestor virus of the HPAI H7N9 viruses originated in the Yangtze River Delta region. However, the insertion of four amino acids into the HA protein cleavage site of an LPAI H7N9 virus occurred in late May 2016 in the Pearl River Delta region. The mutated HPAI H7N9 virus further reassorted with LPAI H7N9 or H9N2 viruses that were cocirculating in poultry. Considering the rapid geographical expansion of the HPAI H7N9 viruses, effective control measures are urgently needed. |
| Databáze: | OpenAIRE |
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