For those of you that attended the American Association of University Women “FUN”draiser in November, you will not be surprised to find the diagram I shared with the green, double-arrow below connecting Swine and Humans in the transmission of influenza genetic material and the ongoing surveillance studies needed to predict the next possible strains of pathogens transmissible to humans. Two days ago, the Proceedings of the National Academy of Sciences published a peer-reviewed and submitted article sharing surveillance data from 2011-2018. A link to the article and summary of the findings are summarized here.
SIGNIFICANCE:
Pigs are intermediate hosts for the generation of pandemic influenza virus. Thus, systematic surveillance of influenza viruses in pigs is a key measure for pre warning the emergence of the next pandemic influenza. Here, we identified a reassortant EA H1N1 virus possessing pdm/09 and TR-derived internal genes, termed as G4 genotype, which has become predominant in swine populations since 2016. Similar to pdm/09 virus, G4 viruses have all the essential hallmarks of a candidate pandemic virus. Of concern is that swine workers show elevated seroprevalence for G4 virus.
Controlling the prevailing G4 EA H1N1 viruses in pigs and close monitoring in human populations, especially the workers in swine industry, should be urgently implemented.
AUTHORS:
Honglei Sun, Yihong Xiao, Jiyu Liu, Dayan Wang, Fangtao Li, Chenxi Wang, Chong Li, Junda Zhu, Jingwei Song, Haoran Sun, Zhimin Jiang, Litao Liu, Xin Zhang, Kai Wei, Dongjun Hou, Juan Pu, Yipeng Sun, Qi Tong, Yuhai Bi, Kin-Chow Chang, Sidang Liu, George F. Gao, and Jinhua Liu
ABSTRACT:
Pigs are considered as important hosts or “mixing vessels” for the generation of pandemic influenza viruses. Systematic surveillance of influenza viruses in pigs is essential for early warning and preparedness for the next potential pandemic. Here, we report on an influenza virus surveillance of pigs from 2011 to 2018 in China, and identify a recently emerged genotype 4 (G4) reassortant Eurasian avian-like (EA) H1N1 virus, which bears 2009 pandemic (pdm/09) and triple-reassortant (TR)-derived internal genes and has been predominant in swine populations since 2016. Similar to pdm/09 virus, G4 viruses bind to human-type receptors, produce much higher progeny virus in human airway epithelial cells, and show efficient infectivity and aerosol transmission in ferrets. Moreover, low antigenic cross-reactivity of human influenza vaccine strains with G4 reassortant EA H1N1 virus indicates that preexisting population immunity does not provide protection against G4 viruses. Further serological surveillance among occupational exposure population showed that 10.4% (35/338) of swine workers were positive for G4 EA H1N1 virus, especially for participants 18 y to 35 y old, who had 20.5% (9/44) seropositive rates, indicating that the predominant G4 EA H1N1 virus has acquired increased human infectivity. Such infectivity greatly enhances the opportunity for virus adaptation in humans and raises concerns for the possible generation of pandemic viruses.
AUTHOR AFFILIATIONS:
Honglei Sun a,1, Yihong Xiao b,1, Jiyu Liu a,1, Dayan Wang c,d, Fangtao Li a, Chenxi Wang a, Chong Li a, Junda Zhu a, Jingwei Song a, Haoran Sun a, Zhimin Jiang a, Litao Liu a, Xin Zhang a, Kai Wei b, Dongjun Hou a, Juan Pu a, Yipeng Sun a, Qi Tong a, Yuhai Bi e, Kin-Chow Chang f, Sidang Liu b, George F. Gao c,d,e,2, and Jinhua Liua,2
a Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, 100193 Beijing, China;
b Department of Fundamental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 271000 Tai’an, China;
c Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 102206 Beijing, China;
d World Health Organization Collaborating Center for Reference and Research on Influenza, 102206 Beijing, China;
e Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Center for Influenza Research and Early-Warning, Chinese Academy of Sciences, 100101 Beijing, China;
f School of Veterinary Medicine and Science, University of Nottingham, Loughborough LE12 5RD, United Kingdom
Contributed by George F. Gao, April 28, 2020
(sent for review December 9, 2019; reviewed by Ian H. Brown and Xiu-Feng Henry Wan)
DOI: