H9N2 influenza viruses possessing H5N1-like internal genomes continue to circulate in poultry in southeastern China

Citation
Y. Guan et al., H9N2 influenza viruses possessing H5N1-like internal genomes continue to circulate in poultry in southeastern China, J VIROLOGY, 74(20), 2000, pp. 9372-9380
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
JOURNAL OF VIROLOGY
ISSN journal
0022-538X → ACNP
Volume
74
Issue
20
Year of publication
2000
Pages
9372 - 9380
Database
ISI
SICI code
0022-538X(200010)74:20<9372:HIVPHI>2.0.ZU;2-J
Abstract
The transmission of H9N2 influenza viruses to humans and the realization th at the A/Hong Kong/156/97-like (H5N1) (abbreviated HK/156/97) genome comple x may be present in H9N2 viruses in southeastern China necessitated a study of the distribution and characterization of H9N2 viruses in poultry in the Hong Kong SAR in 1999. Serological studies indicated that H9N2 influenza v iruses had infected a high proportion of chickens and other land-based bird s (pigeon, pheasant, quail, guinea fowl, and chukka) from southeastern Chin a. Two lineages of H9N2 influenza viruses present in the live-poultry marke ts were represented by A/Quail/Hong Kong/G1/97 (Qa/HK/G1/97)-like and A/Duc k/Hong Kong/Y280/97 (Dk/HK/Y280/97)-like viruses. Up to 16% of cages of qua il in the poultry markets contained Qa/HK/G1/97-like viruses, while about 5 % of cages of other land-based birds were infected with Dk/HK/Y280/97-like viruses. No reassortant between the two H9N2 virus Lineages was detected de spite their cocirculation in the poultry markets. Reassortant viruses repre sented by A/Chicken/Hong Kong/G9/97 (H9N2) were the major H9N2 influenza vi ruses circulating in the Hong Kong markets in 1997 but have not been detect ed since the chicken slaughter in 1997. The Qa/HK/G1/97-like viruses were f requently isolated from quail, while Dk/HK/Y280/97-like viruses were predom inately associated with chickens. The Qa/HK/G1/97-like viruses were evolvin g relatively rapidly, especially in their PB2, HA, NP, and NA genes, sugges ting that they are in the process of adapting to a new host. Experimental s tudies showed that both H9N2 lineages were primarily spread by the aerosol route and that neither quail nor chickens showed evidence of disease. The h igh prevalence of quail infected with Qa/HK/G1/97-like virus that contains six gene segments genetically highly related to HK/156/97 (H5N1) virus emph asizes the need for surveillance of mammals including humans.